Control Techniques: Modular Drive System Installation Overview

Control Techniques: Modular Drive System Installation Overview

MRO Electric and Supply has new and refurbished Control Techniques MDS Drives available now, and also offers repair pricing. For more information, please call 800-691-8511 or email sales@mroelectric.com.

 

Installation MDS Installation Overview

 

 

 

Step 1: Power Module Backplane Installation

Step 2: Drive Module Backplane Installation

Step 3: Power Module Backplane High Power Connections

• AC Input Power • Transformer Sizing ( if required)

• External Shunt Connection (if required)

• Line Fusing and Wire Size

Step 4: Drive Module High Power Connections

• Motor Power Cable

Step 5: Power Module Installation

Step 6: Drive Module Installation

Step 7: Power and Drive Module Low Power Connections

•Logic Power Sizing

• Digital I/O and Logic Power (user supplied)

• AC Interlock • Digital I/O

• Command Signals

• Motor Brake

• Feedback

• Communications

Step 8: Power Up

Ensure the mounting location, cable layout, environmental and electromagnetic received proper installation before starting the actual installation of the MDS. By referring to “Basic Installation Notes”, guidelines and requirements are more-likely met.

Basic Installation Notes

You are required to follow all safety precautions during start-up such as providing proper equipment grounding, correctly fused power and an effective Emergency Stop circuit which can immediately remove power in the case of a malfunction. See the “Safety Considerations” section for more information.

Introduction

Modular Drive System (MDS)

The Modular Drive System (MDS) is a 480V servo system comprised of a common Power Module and up to eight Drive Modules. The modular approach provides an optimum solution for each application. The Power Module provides the AC rectification and provides DC bus power for up to eight Drive Modules. The common power supply minimizes installation space and cost because there is only one AC Input, one Contactor, one set of AC fuses and one AC line Filter per system. Each Power and Drive Module mounts on an innovative backplane that provides the connection for the DC Bus and Logic Power, this minimizes installation time. A compact installation is possible because the backplanes mount next to each other, removing the need for space between each axis.

Fuses (included) are mounted directly on each Drive Module backplane to provide individual protection for each axis. The Drive Modules can operate as base drives providing Velocity, Torque and Pulse/ Direction operations. For positioning and more advanced applications with more functionality add an FM module to that axis for control. FM modules give the MDS “snap-on” functionality for indexing (FM-2), programming (FM-3) and advanced programming (FM- 4). For applications that require Fieldbus, the FM-3 and FM-4 modules can be ordered with DeviceNet or Profibus options. Regardless of the control needed commissioning and programming is made easy with our FREE PowerTools FM and PowerTools Pro software.

PowerTools is a Windows® based software that makes extensive use of drag and drops editing, tabbed and hierarchal views, and on-line help to create a “Motion Made Easy” experience. Commissioning time is minimized because the tuning of the drives is completed with system parameters, Inertia mismatch, Friction, and Response. The State-Space algorithm uses the system parameters and motor map (DDF files) to make a robust control system that is capable of 10:1 inertia mismatch applications out of the box. For higher mismatches, up to 50:1, a simple adjustment to the Inertia and Response parameters will provide the desired performance. PowerTools has complete diagnostics and status indicators for quick troubleshooting. System problems can be quickly identified with the status indicators and I/O on the Power and Drive Modules, along with fault logging stored in the non-volatile memory, minimizing startup time.

The MDS is able to use Control Techniques motors as well as other manufacturers motors. Setup with a Control Techniques’ motor is done by selecting the desired motor in PowerTools. Control Techniques has two lines of motors, MH and Unimotor motors to provide an optimal solution for each application.

 

Cable to Enclosure Shielding

Shielded motor, feedback, serial communications and external encoder cables were used for compliance testing and are necessary to meet the EMC requirements. Each cable shield was grounded in the enclosure wall by the type of grommet shown in Figure 2.

 

Control Techniques: Modular Drive System Installation Overview

 

Control Techniques: Modular Drive System Installation Overview

AC Line Filters

The AC line filters are necessary to comply with CE emission standards. The MDS was tested with the filters presented in the table below and recommended by Control Techniques*.

 

Control Techniques: Modular Drive System Installation Overview

View MP-1250 by clicking here

View MP-2500 by clicking here 

View MP-5000 by clicking here

 

* Consult factory for availability of the MLF-020-00 and MLF-035-00. The filter recommended for the MP-5000 can be used for smaller Power Modules.

Toroids

In applications using long cables additional measures to reduce EMI might be necessary, such as toroids on the motor cable. Based on Control Techniques compliance test results, the following guidelines should be used.

 

Control Techniques: Modular Drive System Installation Overview

Control Techniques recommends using Rasmi toroids in applications with motor cables longer than in table above.

 

Control Techniques: Modular Drive System Installation Overview

 

 

Control Techniques: Modular Drive System Installation Overview

 

 

Panel Layout

 

Control Techniques: Modular Drive System Installation Overview

Power Module Backplane Dimensions

 

Control Techniques: Modular Drive System Installation Overview

Power Module Assembly Dimensions

 

Control Techniques: Modular Drive System Installation OverviewDrive Module Backplane Dimensions

 

Control Techniques: Modular Drive System Installation Overview

 

Control Techniques: Modular Drive System Installation Overview

Drive Module Assembly Dimensions

 

Control Techniques: Modular Drive System Installation Overview

Figure 1: Module Drive System Overview

Power Modules are available in three power ratings

Control Techniques: Modular Drive System Installation Overview

View MP-1250 by clicking here

View MP-2500 by clicking here 

View MP-5000 by clicking here

 

Drive modules are available in five current ratings.

Control Techniques: Modular Drive System Installation Overview

View MD-404 by clicking here

View MD-407 by clicking here

View MD-410 by clicking here

View MD-420 by clicking here

View MD-434 by clicking here

FM Modules

The MDS is designed to accept a line of function modules that further enhance its use in various applications.

• FM-2 Indexing Module enables the user to initiate up to 16 different indexes, jogging, and a single home routine.

• FM-3, FM-3DN, and FM-3PB Programming Modules offer complex motion profiling. A complex motion profile consists of two or more indexes that are executed in sequence such that the final velocity of each index except the last is non-zero. Logical instructions between index statements can provide a powerful tool for altering motion profiles ’on the fly’. The FM-3 can be ordered with DeviceNet or Profibus for Fieldbus applications.

• FM-4, FM-4DN, and FM-4PB Programming Modules offer complex motion profiling, along with multi-tasking user programs. A complex motion profile consists of two or more indexes that are executed in sequence such that the final velocity of each index except the last is non-zero. Logical instructions between index statements can provide a powerful tool for altering motion profiles ’on the fly’. The FM-4 can be ordered with DeviceNet or Profibus for Fieldbus applications.

The FM Function modules define complex motion by a configuration file that includes setups and function assignments. For the FM-3 and FM-4 modules, the configuration file also includes programs. The configuration file is created using PowerTools FM or PowerTools Pro. The FM-2 module uses PowerTools FM software, and all the FM-3 and FM-4 modules use PowerTools Pro software. Setup views have the same look and feel as dialog boxes. The assigning of input and output functions is done through assignments view in the software. PowerTools software is an easy-to-use Microsoft® Windows® based setup and diagnostics tool.

Control Techniques: Modular Drive System Installation Overview

Step 1: Power Module Backplane Installation

Control Techniques: Modular Drive System Installation Overview

Mount the Power Module in the leftmost position using #10 panhead screws. Before tightening the screws holding the backplane to the metal mounting panel, the optional cable strain relief bracket must be installed.

Control Techniques: Modular Drive System Installation Overview

By sliding the bracket behind the backplane so it aligns with the slot of the bracket, the Optional Cable Strain Relief bracket can be installed. The Optional Cable Strain Relief bracket can be secured with a 10# panhead screw.

Step 2: Drive Module Backplane Installation

  1. On the Power Module backplane, loosen the DC Bus screws.Align the Logic connector with the Power Module board, the DC Bus bars with the DC Bus screws and all the tabs on the Drive Module backplane with slots in the Power Module backplane.
  2. Ensure the Drive Module backplane is firmly pushed into the Power Module backplane until the Bus bars are under the DC Bus screws and the backplanes snap together. The backplane side walls of each module should be in contact, and the Power Module backplane board should be plugged into the Drive Module backplane Logic connector.
  3. The bus screws are to be torqued to 8-10 in. lbs
  4. To install the Optional Cable Strain Relief bracket, slide the bracket behind the backplane, aligning the slot with the backplane screw, push until it stops then secure with a #10 panhead screw.
  5. By using 10# panhead screws, secure the Drive Module backplane to the enclosure mounting panel
  6. With the aforementioned 10# panhead screws, secure the Power and Drive Module PE ground tabs
  7. Repeat step 1-7 and continue adding Drive Modules

Step 3: Power Module High Power ConnectionsSystem

Grounding To ensure a safe and quiet electrical installation, good system grounding is imperative. The figure below is an overview of the recommended system grounding. For more information on achieving an electrically quiet installation refer to “Basic Installation Notes” on page 6.

Transformer Sizing

If your application requires a transformer, use the following table for sizing the KVA rating. The values in the table are based on “worst case” power usage and can be considered a conservative recommendation. You can down-size the values only if the maximum power usage is less than the transformer continuous power rating. Other factors that may influence the required KVA rating are high transformer ambient temperatures (>40° C or >104° F) and MDS operation near the maximum speeds.

Control Techniques: Modular Drive System Installation Overview

Line Fusing and Wire Size

You must incorporate overcurrent protection for the AC Input power with the minimum rating shown here. Refer to the table below for recommended fuses and wiring of other equivalent fast blow fuses.

Control Techniques: Modular Drive System Installation Overview

External Shunt Electrical Installation

Shunt Wire Size

Control Techniques: Modular Drive System Installation Overview

Shunt Resistor Connection

Connect the Shunt Resistor to B+ and Shunt terminals on the Shunt connector.

Control Techniques: Modular Drive System Installation Overview

Control Techniques: Modular Drive System Installation Overview

Note:

For proper fuse size refer to table below. Fast blow semiconductor fused rated 700 VDC or higher are recommended (such as Shawmut A70Q). If using Control Techniques’ shunt, MS-510-00 or MS-530-00, refer to Figure 24 for proper connections.

 

Control Techniques: Modular Drive System Installation Overview

Control Techniques: Modular Drive System Installation Overview

Control Techniques: Modular Drive System Installation Overview

Step 4: Drive Module High Power Connections

Motor Power Cable Wiring to the Drive Module

The Motors are equipped with up to three male MS (Military Standard) connectors, one for motor power connections, one for encoder connections and one for the brake (if so equipped).

Motor power connections from the Drive Module to the motor can be made with cables which have a female MS style connector on the motor end and four individual wires and shield that connect to the motor power connector on the bottom of the Drive Module.

 

Control Techniques: Modular Drive System Installation Overview

 

Note:

The motor ground wire and shields must be run all the way back to the amplifier terminal and must not be connected to any other conductor, shield of the ground.

Control Techniques: Modular Drive System Installation Overview

Control Techniques: Modular Drive System Installation Overview

Step 5: Power Module Installation

After all the backplanes are secured with AC Input Power and Motor Power cable connections made, the Power Module must be installed into the backplane.

Orient the Power Module to the top of the module is up and the alignment bars in the Module aligns with the alignment tabs in the backplane. The sheet metal of the Power Module will be on the outside of the alignment tabs.

Firmly press the Power Module into the backplane to ensure good backplane connection. When the Module is completely seated to the backplane, torque the top and bottom retaining screws to 6 – 8 LB IN.

 

Control Techniques: Modular Drive System Installation Overview

Step 6: Drive Module Installation

After the Power Module is installed to its backplane the Drive Modules can be installed to their respective backplanes.

Orient the Drive Module so the top of the module is up and the alignment bars in the Module aligns with the alignment tabs in the backplane. The sheet metal of the Drive Module will be on the outside of the alignment tabs.

Firmly press the Drive Module into the backplane to ensure good backplane connection. When the Module is completely seated to the backplane, torque the top and bottom retaining screws to 6 – 8 LB IN.

 

Control Techniques: Modular Drive System Installation Overview

 

Step 7: Power and Drive Module Low Power Connections

Logic and Digitial I/O Power Sizing

The MDS requires a user-supplied logic power supply, 24 VDC +/- 10%, to power the internal logic of the Power Module and Drive Modules. Use the table below to determine the current requirements of the application.

 

Control Techniques: Modular Drive System Installation Overview

* Control Techniques supplies external master synchronization feedback encoders (Model# SCSLD-XXX) or user-supplied synchronization feedback encoders can be used. The current required to power the synchronization feedback encoder cannot exceed 250 mA @ 5 VDC/ Axis.

The user supply connected to the Power Module provides power for the internal logic of the MDS. The Logic Power is carried through the backplane from the Power Module to the Drive Modules.

A user supply is also required for the Digital I/O power on the Power Module, Drive Modules, and FM Modules. The user supply for Logic Power and Digital I/O Power can be the same supply if desired. However, the input tolerances for Logic Power and Digital I/O are different and may require that the I/O and Logic Power supply be separated. Reference the following Figures for connections

Logic and Digitial I/O Power Connections

In Figures 29 and 30 the MDS is being powered by one power supply. The supply needs to be wired into the Power Module Logic Power Input and Digital I/O Input. Each Drive Module and FM module also require Digital I/O power. The Power Module’s Logic Power Input range is +24VDC +/-10%. The Digital I/O power for all the modules is +10 to 30 VDC. For applications that require Digital I/O power outside the Logic Power Input range refer to Figure 31 and 32.

 

Control Techniques: Modular Drive System Installation Overview

Control Techniques: Modular Drive System Installation Overview

 

Control Techniques: Modular Drive System Installation Overview

In Figures 31 and 32, the MDS Logic and I/O power are separated for applications that have Digital I/O power (+10 to 30VDC) that is out of the Logic Power Range (+24VDC +/-10 %).

 

Control Techniques: Modular Drive System Installation Overview

 

Power Module I/O Connections

 

Control Techniques: Modular Drive System Installation Overview

 

The function of the Power Module is to rectify the AC input and provide the DC bus for the Drive Modules. The Power Module has an integral soft-start circuit to limit the in-rush current when powering up the system. Once the DC bus is charged the Power Module passes a logic signal (System Ready) to the Drive Modules across the backplane allowing the Drive Modules to draw power from the bus. For deceleration of loads that generate more energy than the DC Bus capacitance can store, the Power Module has an integral shunt transistor that can be connected to an external shunt resistor through the shunt connector on the bottom of the backplane.

The Power Module has a built-in processor providing system soft-start control, shunt control and basic self-protection and diagnostic functions such as:

• Excessive AC input voltage

• Loss of AC input voltage phase (single phase operation)

• Over temperature of the rectifier bridge and shunt transistor

• Improper shunt circuit operation or wiring error

Six diagnostic display LEDs controlled by the microprocessor are located on the Power Module front panel as well as the I/O connector with 4 digital outputs, 2 digital inputs, and AC Interlock Relay contacts. The function of these signals can be found on the following pages.

Power Module Status Indicators (LEDs)

 

Control Techniques: Modular Drive System Installation Overview

Logic Power

The Logic Power status indicator (green) is illuminated when the +24VDC logic Power is correctly supplied to the Power Module. If the status indicator is not illuminated verify that the user supply is providing between +21.6 VDC and +26.4 VDC.

System Ready

The System Ready status indicator (green) is illuminated when the system power-up sequence is properly completed. See “Power up Sequence” on page 66.

The System Ready status indicator will blink if one of the AC Input Phases is lost. The system will remain functional in single phase condition. However, it’s strongly undesirable to run the system in single phase mode that can cause severe overheating of the power module components.

If AC power is on and the System-Ready status indicator is not illuminated, one of the following has occurred: Shunt fault, Over-temperature or High VAC Input. These faults are described below.

Shunt Fault

The Shunt Fault status indicator (red) will be illuminated in the case of shunt resistor wiring error or a short circuit condition.

Over Temp

The Over Temp status indicator (red) will be illuminated if continuous RMS power rating of the Power Module is exceeded creating an over-temperature condition. The Power Module needs to be shut down to allow for cooling before the Over Temp condition is not present. This fault may also occur if the ambient temperature exceeds 40o C.

High VAC Input

The High VAC Input status indicator (red) will be illuminated if the AC input Voltage exceeds 528 VAC.

Shunt Active

The Shunt Active status indicator (green) will be illuminated when the Shunt Transistor is on. The Shunt Transistor will turn on under two conditions:

• The Bus voltage exceeds 830 VDC due to regenerative energy during motor deceleration. Shunt Transistor turn off level is 780 VDC.

• The External Shunt Control Input is active in case of emergency stop.

 

Control Techniques: Modular Drive System Installation Overview

 

System Ready

The System Ready output is active (high) when the Power Module has completed the powerup sequence properly. (See Figure 38) Once this signal is active the Drive Module can be enabled. The System Ready output remains high during normal system operation and turns low in case of a system fault.

If AC power is on and System Ready output is low, one of the following has occurred: Shunt fault, Over-temperature fault or High VAC Input. These faults are described below.

Shunt Fault

The Shunt Fault output will be active (high) in the case of shunt resistor wiring error or a short circuit condition.

Over Temp

The Over Temp fault will be active (high) if continuous RMS power rating of the Power Module is exceeded creating an over-temperature condition.

High VAC Input

The High VAC output will be active (high) if the AC input Voltage exceeds 528 VAC.

Drive Module Fault

The Drive Module Fault output will be active (high) if at least one of the Drive Modules is in overcurrent or short circuit condition. In this case, a ’Z’ fault will be displayed on the Drive Module display indicator. The System Ready signal will not be affected by the status of this signal.

Shunt Active

The Shunt Active Output will be active (high) when the Shunt Transistor is on. The Shunt Transistor will turn on under two conditions:

• The Bus voltage exceeds 830 VDC due to regenerative energy during motor deceleration. Shunt Transistor turn off level is 780 VDC.

• The External Shunt Control Input is active in case of emergency stop.

AC Interlock

The AC Interlock relay contacts are closed if +24 VDC Logic Power is supplied to the system. This relay is intended to remove AC power from the system (contacts are open) when one of the faults below occur:

• High VAC Input

or

• Shunt Fault

Control Techniques: Modular Drive System Installation Overview

 

Control Techniques: Modular Drive System Installation Overview

Ext Shunt Control

The External Shunt Control Input (active high) gives the user control of the shunt transistor in case of an emergency stop. When this input is active the shunt transistor will turn on and bleed the bus down through an external shunt resistor.

This Input is disabled when AC Power is supplied to the system

Fault Reset

The Faults Reset Input (active high) allows the user to reset any of three faults without removing +24 VDC Logic Power from the system.

 

Control Techniques: Modular Drive System Installation Overview

Logic Power

The Logic Power is necessary for all internal logic operation of the Power and Drive Modules. The Logic Power input is +24 VDC +/- 10 %. See “Logic and Digitial I/O Power Connections” on page 37 for wiring diagrams.

PE (SHIELD)

The PE connection is a convenient place to connect I/O cable shield. It is the same electrical point as all other PE connections of the MDS. See “System Grounding” on page 23.

I/O

The I/O supply input is used to power the user side of the Power Module I/O. The I/O supply supports +10 to 30 VDC input. See “Logic and Digitial I/O Power Connections” on page 37 for wiring diagrams.

 

Drive Module I/O Connections

Control Techniques: Modular Drive System Installation Overview

The Drive Module draws power from the DC Bus and controls the current flow to the motor. Each Drive Module is configured using PowerTools FM or PowerTools PRO. The Drive Module contains a diagnostic display that provides visible feedback to the current status of the Drive Module. The Drive Module has connections for Digital I/O, Analog I/O, Encoder Feedback, Sync Encoder and the ability to connect FM modules for more functionality.

Input/Output Connector Wiring

Drive Modules are equipped with five optically isolated input lines (one is dedicated to a drive enable function) and three optically isolated output lines. They are designed to operate from a +10 to 30 VDC source. All inputs and outputs are configured as sourcing.

 

Control Techniques: Modular Drive System Installation Overview

 

Control Techniques: Modular Drive System Installation Overview

Motor Brake Wiring

HT and MH motors equipped with brakes have a separate three-pin MS style connector for brake power. The brake power cable (model CBMS-XXX) has an MS style connector on the motor end and three wire leads on the Drive Module end (see Figures 42 and 43). For Unimotors equipped with brakes, the brake wiring is contained in the motor power cable.

You must provide a DC power supply rated at +24 VDC with a 2 amp minimum current capacity for the brake. If you use this voltage source to power other accessories such as I/O or more than one brake, you must increase its current capability.

 

Control Techniques: Modular Drive System Installation Overview

 

Control Techniques: Modular Drive System Installation Overview

Command Connector Wiring

All command and digital I/O signals are available using the 44-pin Command Connector (J5).

If you are interfacing your MDS to an AXIMA 2000 or 4000 multi-axis controller, simply connect the 44-pin connector of your AX4-CEN-XXX cable to the Drive Module and the 25- pin connector to the AXIMA multi-axis controller.

If you are interfacing your MDS to an AXIMA Classic or any other motion controller, you may use either the CDRO-XXX or CMDO-XXX cables or the optional External Connection Interface (ECI-44) which provides a convenient screw terminal connection strip. Connect one end of the CMDX command cable to your Drive Module and the other end to the ECI-44.

 

Control Techniques: Modular Drive System Installation Overview

Control Techniques: Modular Drive System Installation Overview

 

Control Techniques: Modular Drive System Installation Overview

Command Cables

The CMDO, CMDX and CDRO cables are all cables that plug into the Command Connector.

The CMDO and CMDX cables both use the same straight connector style, same color code and carry the full complement of signals available from the Command Connector. The difference is the CMDO cable has a male connector on one end with open wires on the other while the CMDX cable has male connectors on both ends.

For information about CMDO-XXX and CMDX-XXX (18 pair cable) cable wire colors see the “Specifications” section.

The CDRO cable includes only the most commonly used signals to reduce the cable outer dimension and has a connector at only one end. The 45-degree connector design used on the CDRO cable also reduces the enclosure spacing requirement below the Drive Module.

For information about the CDRO-XXX (13 pairs) cable wire colors, see the “Specifications” section.

Analog Command Wiring

 

Control Techniques: Modular Drive System Installation Overview

 

Encoder Output Signal Wiring

The encoder outputs meet RS-422 line driver specifications and can drive up to ten RS-422 signal receivers.

The default encoder output scaling is set to output the actual motor encoder resolutions. The standard MH and HT motors have 2048 lines per revolution. With PowerTools this resolution is adjustable in one line per revolution increments up to the density of the encoder in the motor.

 

Control Techniques: Modular Drive System Installation Overview

 

Pulse Mode Wiring, Differential Inputs

 

Control Techniques: Modular Drive System Installation Overview

 

Pulse Mode Wiring, Single Ended Inputs

 

Control Techniques: Modular Drive System Installation Overview

 

 

Control Techniques: Modular Drive System Installation Overview

 

Control Techniques: Modular Drive System Installation Overview

 

Control Techniques: Modular Drive System Installation Overview

Motor Feedback Wiring

Encoder feedback connections are made with the CFCS cable. This cable has an MS style connector on the motor end and a 26-pin high density “D” connector on the Drive Module end. For more information about all feedback, cables see the “Specifications” section.

For A, A, B, B and Z, Z pairs, the CFCS cable uses low capacitance (~10 pf/ft) wire to get a characteristic impedance of 120 ohms. This impedance match is important to minimize signal loss and ringing.

 

Control Techniques: Modular Drive System Installation Overview

The MDS drive can accept differential or single-ended commutation signals: U, V, and W. It the commutation signals are single-ended connect the appropriate signals to U, V, and W. The compliment signals U\, V\ and W\ do not need to be grounded for operation. The signals are pulled to ground internally.

Serial Communications

Serial communications with the MDS is provided through the female DB-9 connector located on the front of the Drive Module. The serial interface is either three wire non-isolated RS- 232C or two wire non-isolated RS-485. RS-485 is also available through the 44-pin Command Connector.

Modbus Communications

The Drive Module’s serial communication protocol is Modbus RTU slave with a 32-bit data extension. The Modbus protocol is available on most operator interface panels and PLC’s.

 

Control Techniques: Modular Drive System Installation Overview

 

Multi-Drop Communications

The RS-485 option (pins 4 and 9) is provided for multi-drop configurations of up to 32 Drive Modules. A multi-drop serial cable, is available, which allows you to easily connect two or more MDS Drive Modules.

 

Control Techniques: Modular Drive System Installation Overview

 

Control Techniques: Modular Drive System Installation Overview

 

Control Techniques: Modular Drive System Installation Overview

Step 8: Power Up Sequence

Verify that all Power and Drive Modules are installed and secured to their respective backplanes.

Power up Sequence

 

Control Techniques: Modular Drive System Installation Overview

 

Control Techniques: Modular Drive System Installation Overview

The MDS is able to handle short drops (glitch) on the AC Input Power without interruption to system operation. If the DC Bus voltage drop is greater than 250 VDC the System Ready Signal will go Low (not Active). If AC Input Power is applied before the DC Bus voltage drops to 60VDC the Power Module will re-enter Soft Start and the Ready Signal will go High (Active) when the Soft Start is complete. If the DC Bus voltage drops below 60VDC the system will need to be reset for the Modules to power-up.

 

Control Techniques: Modular Drive System Installation Overview

Motor Mounting

Motors should be mounted firmly to a metal mounting surface to ensure maximum heat transfer for maximum power output. The mounting surface should be bonded to the single point ground.

For motor dimensions, weights and mounting specifications, see the “Specifications” section.

Drive and Power Module Removal

1. Unplug all I/O and/or cable connections to the Power and Drive Modules.

2. Loosen the Retaining Screws of the module being removed

3. Grasp the top and bottom Integrated Removal Tab of the module.

4. Pull the module from the backplane.

Control Techniques: Modular Drive System Installation Overview

Drive Module Fuse Replacement

 

Control Techniques: Modular Drive System Installation Overview

The Drive Module backplane is equipped with two overcurrent protection fuses with the ratings shown here. Control Techniques recommends fuse type: SHAWMUT® A70QS.

 

Control Techniques: Modular Drive System Installation Overview

View MD-404 by clicking here

View MD-407 by clicking here

View MD-410 by clicking here

View MD-420 by clicking here

View MD-434 by clicking here

Drive Module Backplane Disassembly

These instructions are to remove a Drive Module backplane from another Module backplane. Shown in the figure below is a Power and Drive Module Backplane assembly

Control Techniques: Modular Drive System Installation Overview

1. Remove the Drive Module and the Power Module from their backplanes. For details see “Drive and Power Module Removal” on page 69.

2. Remove the PE ground tab screw and if applicable the Optional Cable Strain Relief screw of the backplane being removed.

3. Remove the screws that secure the backplane to the metal mounting panel. If applicable the Optional Cable Strain Relief can be removed now.

4. Loosen the Bus screws.

5. Insert a flat tipped screwdriver into the slot between backplanes as shown in Fig 64. Push on the screwdriver with enough force to depress the snap tab, at the same time carefully pull the backplane away from the other backplane. The backplanes only need to be separated far enough so the snap tab is unlocked from the other backplane.

6. Insert the screwdriver into the slot on the other end of the backplane and depress the snap tab, carefully pull the backplane away, unplugging the Logic connector from the other backplane.

 

Operational Overview

The Modular Drive System consists of one Power Module and up to eight Drive Modules connected to the Power Module. The Power Module converts the AC Input Power into a DC Bus that is passed across the backplane. The Power Module contains Soft start Circuitry, Shunt Transistor, and Digital I/O. The Digital I/O of the Power Module is pre-defined and there is no software configuration for it.

The Drive Modules are powered by the DC Bus created by the Power Module. The Drive Module contains Digital I/O, Analog I/O, Encoder Signals, Communication Signals, Pulse Direction Inputs, and Status display. The Status display is on the individual drive axis. The Drive Module I/O can be configured using PowerTools FM software. PowerTools FM is a Wndows® based software used for setup and diagnostic tool.

 

Power Module: Power Module Inputs and Outputs

Logic Power: The Logic Power status indicator (green) is illuminated when the +24VDC, +/- 10% Logic Power is correctly supplied to the Power Module.

System Ready: The System Ready status indicator (green) is illuminated when the system power-up sequence is properly completed. The System Ready status indicator will blink if one of the AC Input Phases is lost. The system will remain functional in single phase condition. If AC power is on and the System-Ready status indicator is not illuminated, one of the following has occurred: Shunt fault, Over-temperature or High VAC Input. These faults are described below.

Shunt Fault: The Shunt Fault status indicator (red) will be illuminated in the case of shunt resistor wiring error or a short circuit condition.

Over Temp: The Over Temp status indicator (red) will be illuminated if continuous RMS power rating or the Power Module is exceeded creating an over-temperature condition.

High VAC: Input The High VAC Input status indicator (red) will be illuminated if the AC input Voltage exceeds 528 VAC.

Shunt Active: The Shunt Active status indicator (green) will be illuminated when the Shunt Transistor is on. The Shunt Transistor will turn on under two conditions:

• The Bus voltage exceeds 830 VDC due to regenerative energy during motor deceleration. Shunt Transistor turn off level is 780 VDC.

• The External Shunt Control Input is active in case of emergency stop.

Shunt Operation

The MDS Power Module has an internal shunt transistor with 15A capacity that can be connected to an external shunt resistor to dissipate regenerative energy generated during deceleration of a load. The MDS Power and Drive Modules rely on the bus capacitors to absorb normal levels of regenerative energy.

Control Techniques: Modular Drive System Installation Overview

External Shunt Operation

The connection for an external shunt resistor is between Bus+ (B+) and Shunt Out located on the Power Module.

Drive Module User Interface

The MDS system is setup using PowerTools FM software.

PowerTools FM Software

PowerTools FM software is easy to use Windows-based setup and diagnostics tool. PowerTools FM software provides you with the ability to create, edit and maintain your Drive Module’s setup. You can download or upload your setup data to or from a Drive Module and save it to a file on your PC or print it for review or permanent storage. PowerTools FM software provides two setup views of the Drive Module, EZ Setup, and Detailed Setup. EZ Setup view is intended to be used by most PowerTools FM software users and provides access to all commonly used drive parameters. Detailed Setup view is available for more advanced drive users who need access to all setup options and diagnostic information.

Control Techniques: Modular Drive System Installation Overview

Control Techniques: Modular Drive System Installation Overview

How Motion Works

Below is a list of details related to motion in a Drive Module.

• The Stop input function overrides motion in all operating modes including Pulse and Torque mode. It shifts the mode to Velocity mode and decelerates the axis according to the Stop deceleration ramp.

• The Travel Limits work in all operating modes including; Pulse, Velocity, and Torque modes. • When a Travel Limit has been activated in a particular direction, the uninhibited motion is allowed in the opposite direction.

• The Positive Direction parameter affects all motion by specifying which direction the motor shaft will rotate (CW or CCW) when the command position is increasing.

• When changing modes with Torque Mode Enable input function, no ramping occurs between the two different commands.

• When using Summation mode, the properties of both summed modes are honored.

Functional Overview

The Drive Module is a digital servo drive that provides three basic modes of operation: Pulse, Velocity, and Torque. The Operating Mode selection defines the basic operation of the Drive Module.

External control capability is provided through the use of input and output functions. On the power module these functions are pre-defined and on the Drive Module, these functions may be assigned to any input or output line which may be controlled by external devices, such as a PLC or multi-axis controller, to affect the Drive Module operation.

Drive parameters can be modified using PowerTools FM software or an FM-P. All drive parameters have a pre-assigned Modbus address which allows you to access them using a Modbus interface.

Pulse Mode

In Pulse mode, the Drive Module will receive pulses which are used to control the position and velocity of the motor.

There are three pulse interpretations associated with Pulse mode: Pulse/Pulse, Pulse/ Direction, and Pulse/Quadrature. These selections determine how the input pulses are interpreted by the Drive Module.

Pulse Source Selection

The Drive Module provides two types of pulse input circuits which allow you to choose the appropriate input type to match the device generating the position pulses. The selection is done by wiring to the desired input pins of the Command Connector and setting the Pulse Source selection in the Setup tab.

The Differential setting (default) is perfect for most encoders or upstream Drive Modules. The Single Ended setting is a good match for an open collector driver that requires an external pull up resistor making it ideal for most stepper controllers, PLC stepper cards, and PC computer parallel printer ports. The two hardware input circuits are included in the Drive Module and are accessible through the Drive Module command connector. The differential input circuit is RS-422 compatible making it inherently noise immune while being able to accept pulse rates of up to 2 Mhz per channel.

The single-ended inputs use high noise immunity circuitry and have internal pull-up resistors to the Drive Module’s 5 Volt logic supply so external pull-ups and biasing circuitry is not required. When proper installation techniques are followed as shown below, the differential input setup will provide a more robust and noise immune system than a single-ended input setup.

Differential input is recommended under any of the following conditions:

• Pulse width < 2 µs

• Pulse frequency > 250 kHz

• Pulse command cable length > 25 feet

• Noisy electrical environments

Differential input circuit specifications:

 

Control Techniques: Modular Drive System Installation Overview

 

Single-ended input circuit specifications:

Single-ended input specifications:

1 MHz maximum input frequency

Internal 330 ohm pull-up to 5 Volt (non-isolated)

1.5 Volt low level

3.5 Volt high-level

Output driver requirements:

15 mA sinking (open collector)

5 Volt capacity

Signal common connected to Drive Logic 0V (Sync Encoder Common 0V)

Control Techniques: Modular Drive System Installation Overview

Pulse/Direction Interpretation

In Pulse/Direction interpretation, pulses are received on the A channel and the direction is received on the B channel. If the B is high, pulses received on the A are interpreted as positive changes to the Pulse Position Input. If the B is low, pulses received on the A are interpreted as negative changes to the Pulse Position Input.

Control Techniques: Modular Drive System Installation Overview

 

Pulse/Quadrature Interpretation

In Pulse/Quadrature interpretation, a full quadrature encoder signal is used as the command. When B leads A encoder counts are received they are interpreted as positive changes to the Pulse Position Input. When A leads B encoder counts are received they are interpreted as negative changes to the Pulse Position Input. All edges of A and B are counted, therefore one revolution of a 2048 line encoder will produce an 8192 count change in the Pulse Position Input.

Control Techniques: Modular Drive System Installation Overview

Pulse/Pulse Interpretation

In Pulse/Pulse interpretation, pulses received on the A channel are interpreted as positive changes to the Pulse Position Input. Pulses received on the B channel are interpreted as negative changes to the Pulse Position Input.

Control Techniques: Modular Drive System Installation Overview

Pulse Mode Parameters

The Pulse Position Input parameter shows the total pulse count received by the Drive Module since the last power-up.

The Pulse Position Input, Position Command, Position Feedback Encoder and Position Feedback are initialized to zero on power-up.

Only Position Feedback Encoder can be preloaded serially with a value after power-up. The Pulse Mode Ratio parameter includes a numerator which represents motor revolutions, and a denominator which represents master pulses.

The Pulse Ratio Revolutions is allowed to be negative which reverses all Pulse mode motion. The Pulse Position Input is multiplied by the Pulse Mode Ratio to produce the Position Command.

Following Error/Following Error Limit

The Following Error is the algebraic difference between the Position Command and the Position Feedback. It is positive when the Position Command is greater than the Position Feedback. All accumulated Following Error will be cleared when the Drive Module is disabled. The Following Error Limit is functional in Pulse mode only.

The Following Error Limit can be set using PowerTools FM or an FM-P. This limit is in motor revolutions and has a range of .001 to 10.000 revolutions. The Following Error Limit can be enabled or disabled.

Pulse Mode Following Error

In Pulse Mode, the range of the Following Error is ±2863.3 revolutions. If the Following Error Limit is not enabled and the Following Error exceeds 2863.3 revolutions, the displayed value is limited to this maximum value and will not roll over.

If the Following Error Limit Enable is enabled, the absolute value of the Following Error will be compared to the Following Error Limit. If the limit is exceeded, a fault will be generated. If the Following Error Limit Enable is disabled, the Following Error Limit is not used.

Velocity Mode Following Error

In Velocity mode, the maximum Following Error possible varies based on the gain and torque limit settings. When the Actual Torque Command reaches the maximum possible level, the following error will stop increasing and any additional position error will be dropped. In Velocity mode, when the following error exceeds the Following Error Limit parameter there is no action.

Encoder Feedback and Position Feedback

Encoder Feedback (Position Feedback Encoder) and Position Feedback are two separate parameters which indicate the same physical motor position. Encoder Feedback is the position change since power-up in motor encoder counts and Position Feedback is the total position change since power-up in motor revolutions. The Position Direction parameter setting will change which direction the motor rotates when the position feedback and position command are counting up. In the default setting the position counts up when the motor shaft rotates clockwise (when viewed from the shaft end).

The Encoder Feedback (Position Feedback Encoder) parameter can be pre-loaded serially by setting the Position Feedback Encoder Modbus parameter.

Velocity Mode

Three submodes are associated with Velocity mode: Analog, Presets, and Summation.

Analog Submode

The Analog Input receives an analog voltage which is converted to the Velocity Command Analog parameter using the Full-Scale Velocity, Analog Input Full Scale, and Analog Input Zero Offset parameters. The equation for this conversion is:

VCA = ((AI – AZO) FSV) / AFS

Where:

VCA= Velocity Command Analog (RPM)

AI = Analog Input (volts)

AZO = Analog Input Zero Offset (volts)

FSV = Full Scale Velocity (RPM)

AFS = Analog Input Full Scale (volts)

The Velocity Command is always equal to the Velocity Command Analog in Analog Velocity mode. The Velocity Command is the command received by the velocity closed loop control.

Analog Accel/Decel Limit

This feature in the Analog submode allows you to limit the accel and decel rate when using the analog input for velocity control. This makes it very simple to use the drive in high performance, variable speed, start-stop applications such as Clutch-Brake replacements without requiring a sophisticated controller to control the acceleration ramps. In applications which do not require the drive to limit the ramps such as when using an external position controller, the parameter can be set to “0” (its default value). If the Analog Accel/Decel Limit parameter value is changed during a ramp, the new ramp limit is imposed within the next servo loop update.

The Analog Accel/Decel Limit parameter is accessed on the Velocity tab. Its range is 0.0 to 32700.0 ms/kRPM.

Presets Submode Presets submode provides up to eight digital Velocity Presets and associated Accel/Decel Presets. At any time only one Velocity Preset can be selected. They are selected using the Velocity Preset Line #1, Line #2 and Line #3 input functions (see table below).

Control Techniques: Modular Drive System Installation Overview

When one of the Velocity Presets is selected, the Target Velocity is set equal to the Velocity Preset value and the accel/decel ramp rate is set to the Accel/Decel value associated with that velocity.

If the Velocity Command Preset is not equal to the Target Velocity, an acceleration (or deceleration) ramp is in progress. In this state, the Velocity Command Preset will be increased (or decreased) based upon the acceleration (or deceleration) ramp rate of the selected velocity preset. During the acceleration/deceleration ramp, the At Velocity output function is inactive.

If the Velocity Command Preset is equal to the Target Velocity, all ramping is complete, the Velocity Command Preset is constant and the At Velocity output function is active.

The Velocity Command is always equal to the Velocity Command Preset in Presets submode.

Control Techniques: Modular Drive System Installation Overview

Summation Submode

In Summation submode the Velocity Command is the result of the sum of the Velocity Command Analog and the Velocity Command Preset values.:

 

VC=AC=PC

Where:

VC = Velocity Command

AC = Velocity Command Analog

PC = Velocity Command Preset

Example 1:

Use of Velocity Presets in a phase advance/retard application. Velocity Preset #0 is set to 0 RPM, Velocity Preset #1 is set to +5 RPM, and Velocity Preset #2 is set to -5 RPM. The Analog Input is the command source for a web application where a phase adjustment may be useful. Without interrupting the operation, you may select either Velocity Preset #1 or #2 to speed up or slow down the motor thereby advancing or retarding the phase between the motor and the web material.

Example 2:

Use the Velocity Command Analog as a trim adjustment to the digital Velocity Presets. Velocity Preset #2 is selected with Analog Input at 0, so the Velocity Command Preset and Velocity Command are equal (set to match a conveyor speed). You can use the Analog Input (Velocity Command Analog) as a fine adjust for the Velocity Command to exactly match the conveyor speed.

 

Control Techniques: Modular Drive System Installation Overview

Torque Mode

In Torque mode both the position and velocity loops are disabled and only the torque loop is enabled.

In Torque mode the Drive Module receives an Analog Input which is scaled to the Analog Torque Command by the Full Scale Torque, Analog Input Full Scale, and Analog Input Zero Offset parameters. The equation is:

TC= ((AL-AZO)FST) / AFS

Where:

TC = Torque Command

AI = Analog Input (volts)

AZO = Analog Input Zero Offset (volts)

FST = Full Scale Torque (%)

AFS = Analog Full Scale (volts)

Drive Modifiers

This section describes functions that can modify the operation of the drive.

Stop

The Stop input function, when activated, will cause motion to stop regardless of motor direction or the operating mode. The Stop Deceleration Ramp defines the rate of velocity change to zero speed. Activating the Stop input function causes the drive to change to Velocity mode. Therefore, if you are operating in Torque mode, the Drive Module must be tuned to the load to prevent instability when activating the Stop input function. For example, if an application is operating in Torque mode at 1000 RPM, and the Stop input function is activated with a Stop Deceleration Ramp of 500 ms/kRPM, the motor will decelerate to a stop in 500 ms.

+/- Travel Limits

The + and – Travel Limit input functions will stop motion in the direction indicated by the input function using the Travel Limit Deceleration rate. This feature is active in all modes. When an axis is stopped by a Travel Limit function, it will maintain position until it receives a command that moves it in the opposite direction of the active Travel Limit.

For example, the + Travel Limit will stop motion only if the motor is moving + but allows – motion to move off the limit switch. Conversely, the – Travel Limit will stop motion only if the motor is moving – but allows + motion to move off the limit switch.

If both input functions are active at the same time, no motion in either direction will be possible until at least one of the inputs is released. When either + or – Travel Limit input function is activated, a fault will be logged into the Fault Log, and the Drive Module will display an “L” on the LED diagnostics display on the front of the Drive Module.

Once the axis is driven by the limit switch, the fault will be cleared and the “L” will disappear. If both Travel Limit input functions are activated simultaneously, the Drive Module will respond as if the Stop input function has been activated and will use the Stop Deceleration ramp.

Travel Limit Application Notes

Torque Mode:

If you are operating in Torque mode, the Drive Module must be tuned to the load to prevent instability when activating the Travel Limit input functions.

Host Controller Travel Limits:

If the host controller decelerates the Drive Module faster than the Travel Limit Deceleration ramp, the Drive Module allows the controller to maintain full control of the axis during the deceleration. This results in no following error build up in the controller and easier recovery.

Vertical Loads in Velocity Mode:

In applications with horizontal, counterbalanced or un-counterbalanced vertical loads, the load will hold in position when motion is stopped due to a + or – Travel Limit. The position will be held until the controller commands motion in the opposite direction of the activated Travel Limit.

Vertical Loads in Torque Mode:

In applications with horizontal or counterbalanced vertical loads, the load will hold in position when motion is stopped due to a + or – Travel Limit. The position will be held until the controller commands motion in the opposite direction of the activated Travel Limit.

In applications with un-counterbalanced vertical loads, you must be careful not to set the controller’s torque command to zero when the upper Travel limit is activated. Setting the controllers analog torque command to zero in this situation will command the axis to move off the limit switch causing the load to drop.

If your controller removes the torque command (zeroes the analog command output) when a Travel Limit is activated, you have a number of choices to prevent the load from dropping. All of which require some external logic to determine when the controller can actually take control again.

• Activate the opposite Travel Limit input function, then release it when the controller is operational again.

• Activate the Stop input function, then release it when the controller is operational again.

• Apply the axis brake, then release it when the controller is operational again

Pulse Mode

In applications with horizontal, counterbalanced or un-counterbalanced vertical loads, the load will be held in position when motion is stopped due to a + or – Travel Limit. The position will be held until the controller commands motion in the opposite direction of the activated Travel Limit.

When the travel limits are activated, the Drive Module will decelerate at the Travel Limit Deceleration Ramp and will continue to store all the command pulses received up to ±232 counts. The stored pulses need to be cleared out before the axis will move off the Travel Limit. This can be done if the controller generates command pulses in the direction opposite the activated Travel limit. The stored command pulses can also be cleared by activating both Travel Limit input functions at the same time, activating the Stop input function or disabling the Drive Module for as little as 5 msec (plus any debounce time).

Torque Limiting

The Torque Command is calculated as shown previously, but its value is limited by the Torque Limit parameter and the current foldback function (see “Torque Limit” and “Current Foldback”). The result of this limiting function is Torque Command Actual. This is the command that drives the Power Stage to generate current in the motor. The Torque Limit Active output function is active whenever the Torque Command Actual is less than from the Torque Command. This will be true when motion is stopped due to a Travel Limit input function.

Torque Limit Function

The Torque Limit Enable input function allows an external controller to limit the Actual Torque Command to a lower value. The Torque Limit parameter is active only when the Torque Limit Enable input function is active.

T TL= P MT, P DT, R FL, S FL, P TL

Where:

TTL = Total Torque Limit

PMT = Peak motor torque

PDT = Peak Drive Module torque

RFL = RMS foldback limit (80 percent of continuous system torque rating)

SFL = Stall foldback limit (80 percent of Drive Module stall current rating)

PTL = Programmable Torque Limit

 

If the application requires that the Torque Limit be enabled at all times, the Torque Limit Enable input function may be set up to be Always Active to avoid the use of an input line.

Velocity Limiting

The Drive Module commanded velocity is limited to 112.5% of the motor’s maximum operating speed. This limiting has nothing to do with the Line Voltage setting. Depending on AC supply voltage, it may or may not be possible to get to motor maximum operating speed.

Example 1:

If the Motor Type is an HT-320, the maximum motor speed of the HT-320 is 4000 RPM. If the Line Voltage parameter is set to 230 VAC and the Velocity Limit is equal to 112.5 percent of 4000 RPM or 4500 RPM.

Overspeed Velocity Parameter

Motor speed is continuously monitored against the Overspeed Velocity parameter whether the Drive Module is enabled or not and when the motor speed exceeds the limit or Overspeed Velocity Limit, a fault is issued. The default value for Overspeed Velocity Limit is 13000 RPM.

The Drive Module has an internal overspeed velocity limit. This limit is the maximum of the Overspeed Velocity parameter and 150% of the motor maximum operating speed. For example, an HT-320 with 4000 RPM maximum speed the internal limit is 6000 RPM.

The Overspeed fault will be activated when either one of these two conditions are met:

1. When the actual motor speed exceeds the Overspeed Velocity Limit parameter.

2. If the combination of command pulse frequency and Pulse Ratio can generate a motor command speed in excess of the fixed limit of 13000 RPM. In Pulse mode operation and any Summation mode which uses Pulse mode, the input pulse command frequency is monitored and this calculation is made. For example: with a Pulse Ratio of 10 pulses per motor revolution, the first pulse received will cause an Overspeed fault even before there is any motor motion.

In Motion Velocity

The In Motion Velocity parameter defaults to a value of 10 RPM. If the motor Velocity Feedback is above the In Motion Velocity value, the In + Motion or In – Motion output function is active. When the motor velocity falls below one half of the In Motion Velocity, the In + Motion or In – Motion output function is inactive. The maximum value for In Motion Velocity is 100 RPM and is intended to be used to indicate “in motion” not “at speed”.

Motor Direction Polarity

The direction that the motor turns with a positive command can be changed with the Positive Direction parameter. This can be accessed with PowerTools FM in the EZ Setup tab or Detailed Setup tab. The positive direction by default causes the motor to turn CW as viewed looking at the shaft.

Control Techniques: Modular Drive System Installation Overview

Positive direction is defined as the command which causes the internal position counter to count “Up”. They are:

• A positive analog velocity or torque command (i.e., a higher voltage on the (+) differential input than on the (-) input).

• A positive direction (+) pulse command. • A positive preset velocity or torque command.

Current Foldback

Current foldback is used to protect the motor and Drive Module from overload. There are two levels of current foldback: RMS Foldback and Stall Foldback. RMS and Stall Foldback are displayed on the diagnostic display as a “C” and “c” respectively.

RMS Foldback

RMS foldback protects the motor from overheating. The RMS Foldback parameter models the thermal heating and cooling of the Drive Module and motor based on the commanded current and the motor velocity. On power-up, the RMS Foldback level is zero and is continually updated. When the RMS Foldback level reaches 100 percent, current foldback is activated and the Foldback Active output function is active. Each Drive Module is designed to deliver up to 300 percent of the motor’s continuous torque for no less the two seconds when running at 100 RPM or more. If only 150 percent of continuous torque is required, several seconds of operation before RMS foldback is typical.

During current foldback, the Torque Command Actual will be limited to 80 percent continuous motor torque. Current foldback is canceled when the RMS Foldback level falls below 70 percent. This could take several seconds or several minutes depending on the load. The RMS Foldback value is dependent on both torque and velocity.

At low speeds (<20 percent of maximum motor speed) the RMS Foldback will closely follow the Torque Command Actual. At high speeds (>50 percent of maximum motor speed) the RMS Foldback will read higher than the Torque Command Actual.

The time constant for RMS Foldback is 10 seconds. This means that if the load is 150 percent of continuous, it will take about 10 seconds to reach the foldback trip point.

Control Techniques: Modular Drive System Installation Overview

Stall Foldback

Stall Foldback prevents overheating of the Drive Module. It activates in any mode when the motor velocity is 100 RPM or less and the Torque Command causes the current to exceed the stall current threshold for 100 ms or more.

Stall Foldback will also be triggered when the drive sees repeated high currents in one of the three motor phases. This can occur when a motor is indexed back and forth between two of its electrical poles.

• For 4 pole motors this distance is 90° mechanical.

• For 6 pole motors this distance is 60° mechanical.

• For 8 pole motors this distance is 45° mechanical.

Once Stall Foldback is activated, the drive current is reduced to 80 percent of the stall current threshold until the Torque Command Actual is reduced to less than 70 percent of the stall current threshold for about 200 ms or until the motor velocity exceeds 100 RPM.

Brake Operation

Motor brake operation is controlled by the Brake Release and Brake Control input functions. These input functions can be used together to control the state of the Brake output function. The table below shows the relationship between the Brake input and Brake output functions.

Control Techniques: Modular Drive System Installation Overview

Brake Release Input Function:

The Brake Release input function will release the brake under all conditions. When this input function is “On”, the Brake output function will be “On” (i.e., release brake). This input function overrides all other brake control, thus allowing the brake to be released while a fault is active or the power stage is disabled. See also Brake output function.

Brake Control Input Function:

This input function, when active, will engage the brake unless overridden by the Brake Release input function. This input lets you externally engage the brake while allowing the Drive Module to also control the brake during fault and disabling conditions.

Brake Output Function:

The Brake output function is used to control the motor holding brake. If the Brake output function is “Off”, the brake is mechanically engaged. When the brake is engaged, the diagnostic display on the front of the Drive Module will display a “b”. The Drive Module outputs are limited to 150 mA capacity, therefore, a suppressed relay is required to control motor coil. Control Techniques offers a relay, model BRM-1.

Analog Command Input

The Analog Command Input can be used as a velocity or torque command. The Drive Module accepts a ±10 VDC differential analog command on pins 14 and 15 of the Command Connector and has 14 bits of resolution. The Analog Inputs Bandwidth, Analog Full Scale and Analog Input Zero Offset parameters are applied to the Analog Input to generate either an analog velocity or torque command. These three parameters can be edited using PowerTools FM, an FM-P or serially using Modbus.

 

Bandwidth: The value of the parameters sets the Low Pass Filter cutoff frequency applied to the analog command input. Signals that exceed this frequency are filtered at a rate of 20 dB/decade.

Analog Full Scale: This parameter specifies the full-scale voltage for the analog input. When the Drive Module receives an analog command input equal to the Analog Input Full Scale parameter, the Drive Module will command either Full-Scale Velocity or Full-Scale Torque depending on the operating mode.

Analog Zero Offset: Analog Input Zero Offset is used to null any input voltage that may be present at the Drive Module when a zero velocity or torque is commanded by a controller. The amount of offset can be read with PowerTools FM software or an FM-P using the following procedure:

1. Provide the zero velocity command to the analog command input on the command connector.

2. Read the Analog Input Value.

3. Enter the Analog Input Value in the Analog Input Zero Offset.

Control Techniques: Modular Drive System Installation Overview

Analog Outputs

The Drive Module has two 8 bit Analog Outputs which may be used for diagnostics, monitoring or control purposes. These outputs are referred to as Channel 1 and Channel 2. They can be accessed from the Command Connector on the Drive Module or from the diagnostics output pins located on the front of the Drive Module. Each Channel provides a programmable Analog Output Source.

Analog Output Source options are:

• Velocity Command

• Velocity Feedback

• Torque Command (equates to Torque Command Actual parameter)

• Torque Feedback • Following Error

Default Analog Output Source:

Control Techniques: Modular Drive System Installation OverviewEach channel includes a programmable Analog Output Offset and an Analog Output Scale. This feature allows you to “zoom in” to a desired range effectively increasing the resolution. The units for both of these parameters is dependent upon the Analog Output Source selection.

Analog Output Offset units:

• Velocity Command = RPM

• Velocity Feedback = RPM

• Torque Command = Percent of continuous torque for selected motor

• Torque Feedback = Percent of continuous torque for selected motor

• Following Error = Revs

Analog Output Scale units:

• Velocity Command = RPM/volt

• Velocity Feedback = RPM/volt

• Torque Command = Percent of continuous torque/volt for selected motor

• Torque Feedback = Percent of continuous torque/volt for selected motor

• Following Error = Revs/volts

Example:

You could use the Analog Outputs to accurately measure velocity overshoot. For example, to measure a target velocity of 2000 RPM at a resolution of ±10 V = ±200 RPM do the following.

1. Selected Velocity Feedback from the Analog Output Source

2. Set the Analog Output Offset to 2000 RPM 3

. Set the Analog Output Scale to 20 RPM/VOLT This will provide an active range from ±10 Volts to represent 1800 to 2200 RPM. Therefore, the measured resolution has been increased.

Drive Module Digital Inputs and Outputs

External control capability is provided through the use of input and output functions. These functions may be assigned to any input or output line. After they are assigned to lines, external controllers such as a PLC or multi-axis controllers may be used to affect or monitor the Drive Module operation.

Drive Modules are equipped with five optically isolated input lines (one dedicated to a Drive Module Enable function) and three optically isolated output lines. All inputs and outputs are compatible with sourcing signals (active = + voltage) and are designed to operate from a +10 to 30 VDC. You are responsible for limiting the output current to less than 150 mA for each digital output.

These input and output lines can be accessed through the removable 10-pin I/O Connector and through the 44-pin Command Connector.

Input Function Active State

The active state of an input function can be programmed to be “Active Off” or “Active On” using PowerTools FM. Making an input function “Active On” means that it will be active when +10 to 30 VDC is applied to the input line it is assigned to and is inactive when no voltage is applied to the line. Making an input function “Active Off” means that it will be active when no voltage is applied to the input line and inactive while +10 to 30 VDC is being applied. You can also make an input function “Always Active”, which means that it is active regardless of whether or not it is assigned to an input line and if you assign it to an input line, it will be active whether or not voltage is applied to that line. This is useful for testing the Drive Module operation before I/O wiring is complete.

Input Line Debounce Time

You can program a “Debounce Time” which means the line will need to be active for at least the debounce time before it is recognized. This feature helps prevent false triggering in applications with high ambient noise.

Control Techniques: Modular Drive System Installation Overview

Output Line Active State

The default active state of an output line is “Active On”. This means that the output line will supply a voltage when the result of the OR’ed output function(s) assigned to that output line is activated by the Drive Module.

Making an output line “Active Off” means that the line will be “Off” (not conducting) when the result of the OR’ed output function(s) assigned to that output line is active and will supply a voltage when the output function is inactive.

Input Functions Travel Limit + or –

The + and – Travel Limit input functions will stop motion in the direction indicated by the input function using the Travel Limit Deceleration rate. This feature is active in all modes. When an axis is stopped by a Travel Limit function, it will maintain position until it receives a command that moves it in the opposite direction of the active Travel Limit.

For example, the + Travel Limit will stop motion only if the motor is moving + but allows – motion to move off the limit switch. Conversely, the – Travel Limit will stop motion only if the motor is moving – but allows + motion to move off the limit switch.

If both input functions are active at the same time, no motion in either direction will be possible until at least one of the inputs is released.

When either + or – Travel Limit input function is activated, a fault will be logged into the Fault Log, and the Drive Module will display an “L” on the LED diagnostics display on the front of the Drive Module. Once the axis is driven by the limit switch, the fault will be cleared and the “L” will disappear.

If both Travel Limit input functions are activated simultaneously, the Drive Module will respond as if the Stop input function has been activated and will use the Stop Deceleration ramp.

The Stop input function, when activated, will cause motion to stop regardless of motor direction or the operating mode. The Stop Deceleration Ramp defines the rate of velocity change to zero speed.

Activating the Stop input function causes the Drive Module to change to Velocity mode. Therefore, if you are operating in Torque mode, the Drive Module must be tuned to the load to prevent instability when activating the Stop input function.

For example, if an application is operating in Torque mode at 1000 RPM, and the Stop input function is activated with a Stop Deceleration Ramp of 500 ms/kRPM, the motor will decelerate to a stop in 500 ms.

Velocity Preset Lines 1, 2 and 3

The Velocity Preset Lines are used to select one of the eight pre-defined velocities using the binary selection patterns shown below.

If you select a different Preset Velocity, the Drive Module will immediately ramp to the new velocity using the new acceleration ramp without stopping.

Control Techniques: Modular Drive System Installation Overview

Control Techniques: Modular Drive System Installation Overview

Torque Limit Enable

This input function, when active, causes the Torque Command to be limited to the value of the Torque Limit parameter. The Torque Limit can be made “Always Active” by checking the Always Active checkbox on the Inputs tab.

Brake Release

This input function will release the brake under all conditions. If this input function is active, the Brake output function is switched to active (i.e., release brake). This overrides all other brake control, thus allowing the brake to be released while a fault is active or the power stage is disabled.

Brake Control

This input function, when active, will engage the brake unless overridden by the Brake Release input function. This input function lets you externally engage the brake while allowing the Drive Module to also control the brake during fault and disabling conditions.

Torque Mode Enable

This input function, when active, causes the Drive Module to change operating mode to torque mode. When this input function is deactivated the default operating mode is enabled with no transitional ramping.

Output Functions

These outputs are active when the associated Travel Limit input function is active.

Brake

This output function is used to control the motor holding brake. If the Brake output is “Off”, the brake is mechanically engaged.

Foldback Active

This output function is active when the Drive Module is limiting motor current. If the RMS Foldback value exceeds 100 percent of the continuous rating, the current foldback algorithm will limit the current delivered to the motor to 80 percent of the continuous rating.

Drive OK

This output function is active whenever no fault condition exists. Travel Limits and the Drive Module Enable have no effect on this output function.

In Motion + or –

This output function is active whenever the motor is turning at a velocity greater than the In Motion Velocity parameter in the + or – direction respectively. The default value of In Motion Velocity is 10 RPM. Hysteresis is used to avoid a high frequency toggling of this output function. This function is deactivated when the motor velocity is less than 1/2 of the In Motion Velocity parameter.

Power Stage Enabled

This output is active when the Drive Module is OK and enabled. It will go inactive when anything happens to disable the output power stage.

Fault

This output function is active whenever a Drive Module fault condition exists. The Travel Limits will also cause this output function to be active.

At Velocity

This output function is active whenever the motor is at the desired velocity (i.e., acceleration or deceleration is complete). This output is only associated with Velocity Preset Velocities.

Torque Limit Active

This output is active if the Torque Command exceeds the specified Torque Limit value. Refer to Torque Limiting in the Operating Overview section of this manual.

Velocity Limiting Active

This output function is active when the Actual Velocity Command is being limited. The velocity limit is dependent upon the maximum motor speed for the Motor Type selected. If the Actual Velocity Command exceeds the velocity limit, the command will be limited and the Velocity Limiting Active output function will be active.

Torque Level 1 and 2 Active

These outputs are active if the Torque Command exceeds the respective Torque level value.

Temperature Current Limit Active

The Temperature Current Limit Active Output will turn on when the measured heatsink temperature is above 70° C. This output will limit the Drive Module Peak Current available to 170% of Continuous Current. This limitation only happens in the MD-410, MD-420 and MD- 434 Drive Modules. This Output will stay active until the heatsink has had time to cool down to 60° C.

 

 

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