Category Archives: Unidrive Classic

UD55 Small Option Module for Control Techniques Unidrives

The UD55 Cloning Small Option Module can store up to eight parameters-sets which contain all the read–write parameters for a Drive, and include those in Menus 16 & 20, when applicable. These parameter sets can be individually recalled for loading onto the same or another drive.

The cloning of drives can only be performed when the operating mode (Open-loop, Closed-loop Vector, Servo or Regen) of the destination drive is the same as that of the source drive. The UD55 must be fitted in the small option module bay of the Unidrive. All connections to the drive are made by a multi-way connector. Connections from external equipment are made to a plug-in 16-way screw-terminal block on the option module. Some parameters have a profound effect on the operation of the Unidrive. They must not be altered without careful consideration of the impact on the controlled system. Measures must be taken to prevent unwanted changes due to error or tampering.

UD55 Installation

1. Disconnect the AC supply from the Drive.
2. Check that the exterior of the UD55 is not damaged, and that the multi-way connector is free from dirt and debris. Do not fit a damaged or dirty UD55 in a Unidrive.
3. Remove the terminal cover from the Drive.
4. If a small option module is already fitted in the Unidrive, grip the recesses at the ends of the module and pull the module out of the Drive. Keep the module for re-fitting.
5. Position the multi-way connector on the rear of the UD55 over the connector in the Drive (see figure below), and press on the thumb pad to push the UD55 into place.

UD55 Installation
UD55 Installation

Saving Parameters

If the Drive trips and a trip code is displayed while this procedure is being followed, ensure that all the required parameters have been set up in the source Drive and that new parameter values have been saved.
If a small option module was fitted in the Drive, its associated Menu 16 parameters will be copied to the UD55 in addition to the parameters in the other menus.
1. Insert the UD55 in the source Drive (refer to Chapter 3, Inserting theUD55 in a Drive).
2. Ensure terminal 30 of the Drive Signal connector is open-circuit so that the Drive does not become enabled when powered-up.
3. On the UD55 connector, connect terminal 40 directly to terminal 41 to enable the save function (see Figure 2).
4. Re-fit the terminal cover to the Drive.
5. Connect the AC supply to the Drive.
6. Decide which parameter-set number is to be used in the UD55. If a parameter-set already contains parameter values, these will be over-written without warning. It is recommended that a record is made of at least the following for each parameter-set number:
• A means of identifying the configuration of the source Drive
• The model size of the source Drive
• The type(s) of option module(s) fitted
• Motor ratings
7. Set parameter .00 (in any menu) at 300X, where X is the required parameter-set number (1 to 8).
8. Press . The parameter values are now copied (saved) to the UD55.
Saving takes approximately 5 seconds. When it has finished, parameter .00 returns to zero.
9. It is recommended that parameter 11.38 is set at the number of the parameter-set (value of X in step 7) and the value of parameter 11.40 UD55 full parameter check sum noted, as a means of identifying the parameter-set at a later date.
10. Disconnect the AC supply from the Drive.
11. Remove the terminal cover.
12. Disconnect the link between terminals 40 and 41 on the UD55 connector.
13. Remove the UD55 from the Drive.
14. If a small option module was previously fitted in the Drive, re-fit the module.
15. Replace the terminal cover.
16. The Drive can now be used.

MRO Electric provides sales and support for Control Techniques Unidrives and their Option Modules. To request a quote or for more information, visit our UD55 Product Page or call 800-691-8511.

Industrial Legacy Systems

Legacy Systems: Maintenance

Maintaining and upgrading legacy systems is one of the most difficult challenges industrial and manufacturing managers face today. Constant technological change often weakens the business value of legacy systems, which have been developed over the years through huge investments. Managers struggle with the problem of modernizing these systems while keeping their functionality intact. Despite their obsolescence, legacy systems continue to provide a competitive advantage through supporting unique industrial processes. Routine checks allow for preventative maintenance, and for replacement parts to be ordered before they are desperately needed. Here at MRO Electric and Supply, we stock a large number of classic and legacy products which can be shipped in record time.

Legacy Systems: IoT

When new technologies arise, engineers simply cannot uproot existing systems. However, some legacy controls can be connected to the Internet of Things. This allows for a high level of data acquisition which can be stored, processed, and analyzed. Several IoT products can also support remote monitoring and control. Many Modicon Quantum Series products have an Ethernet port that allows for this upgraded connectivity. However, not every legacy system has these capabilities.

Legacy Systems: Security

Targeted attacks on industrial systems always remain a threat as our society plows forward into the computer-driven Information Age. Securing legacy systems that were designed to communicate point to point is a enormous challenge. Many of these older systems were installed pre-internet era, are not designed for connectivity, and have no means of authenticated commands that are received. System interruptions for security updates can be difficult and costly, and downtime is expensive. It is always a challenge to find ways to increase security for legacy systems. One important tip is to always keep the software for connected legacy systems updated with the most current version.

Legacy Systems: Looking Forward

Although replacement supplies and remanufactured parts can be ordered for many years to come, it is important to keep in mind that no legacy system will last forever. In this current sluggish world economy, often the best answer is a well-planned, slow and steady upgrade.

If you need a replacement part for any of your industrial classic or legacy systems, please email or call 1-800-691-8511.

UNI3404: Beyond the User Manual

The UNI3404 is available with a number of option modules, which increase its flexibility and make it suitable for a very wide range of applications. These modules are briefly described in the following paragraphs. For full details refer to UNI3404 manual that is supplied with each of them. The modules are in two physical formats and are known as Large Option Modules (LOM) and Small Option Modules (SOM). Each Undrive may be fitted with one LOM and one SOM.

Unidrive UNI3404 Large Option Modules
  1. UD78 High Precision Analog Input Module. (LOM):
    • This module provides the following features: a) Infinite resolution analog input for precision speed and position control. Large Option Module Small Option Module 1. Introduction 11 b) RS485 communication port. c) Back up supply connector (requires user provided 24VDC) to maintain power to the drive control circuits and encoder feedback when the 3 phase input to the drive is disconnected.
  2. UD70 Co-Processor Module (LOM)
    • The UD70 is an Intel 960 based co processor module that allows the user to write programs in both IEC1131 ladder / Function Block Diagram and Drive Programming Language (DPL) to provide 1.5 axis motion control and sequence control. This is accomplished using the SyPT programming tool on a PC. The module is fitted with an RS232 programming port for this purpose. It also has an RS485 port for general use and this supports the ANSI protocol as a slave or master controller and ModBus RTU as a slave only.
  3. UD71 Serial Communications Module (LOM)
    • The UD71 provides simple serial communication and has both RS232 and RS485 ports.
  4. UD73 Profibus Interface Module (LOM)
    • The UD73 provides full UD70 co-processor functionality and additionally allows the drive to be connected to a Profibus DP network running at speeds up to 1.5 Mbaud.
  5. UD74 Interbus-S Interface Module (LOM)
    • The UD74 provides full UD70 co-processor functionality and additionally allows the drive to be connected to an Interbus-S network at a fixed data rate of 500 Kbaud.
  6. UD75 CTNet Interface Module (LOM)
    • The UD75 provides full UD70 co-processor functionality and additionally allows connection to a CTNet nework. CTNet is Control Techniques fully de-centralized peer to peer fieldbus. This allows implementation of a fully distributed control system with no central PLC controller required.
  7. UD76 Modbus Plus Interface Module (LOM)
    • The UD76 provides full UD70 co-processor functionality and additionally allows connection to a Modbus Plus network.
  8. UD77 DeviceNet interface module (LOM)
    • The UD77 provides full UD70 co-processor functionality and additionally allows connection to a DeviceNet network.
  9. CAN interface module
    • This is based on the UD77 hardware but has different firmware to allow the user to communicate through the CAN physical layer but using his own protocol written using the SyPT toolkit.
  10. CanOpen interface module
    • This is based on the UD77 hardware but the firmware is changed so that the network uses the CanOpen protocol.
Unidrive UNI3404 Small Option Modules
  1. UD50 Extended I/O module
    • This module provides the following additional I/O capability:
      • a) qty. 3, 24VDC digital inputs.
      • b) qty. 3, dual function (user selectable) 24VDC digital inputs / outputs. Rated at 30mA when configured as outputs.
      • c) qty. 2, 10 bit plus sign analog inputs +10 to –10VDC
      • d) qty. 1, analog output +10 to –10VDC.
  2. UD51
    • Second encoder module In servo mode this provides the drive with the following additional capabilities:
      • a) Allows use of a second incremental encoder as a master reference input for digital lock, Electronic Gear box and camming functions.
      • b) Alternatively the UD51 may be configured for frequency and direction input to be used as the drive speed reference.
  3. UD52 Sin/Cos encoder module
    • The UD52 allows a servomotor fitted with a sin/cos encoder to be used. This provides an interpolated resolution of up to 1,048,576 ppr when used with a 512 pulse sin cos encoder and also allows use of an optional 4096 revolution absolute encoder. The Unimotor is available with these encoders fitted as a standard option.
  4. UD53 Resolver Module
    • The UD53 allows use with a servomotor having resolver feedback. This is much more rugged than an encoder and therefore suitable for use in harsh environments. The UD53 can operate with resolver having either 2:1 or 3:1 turns ratio (primary : secondary)
  5. UD55 Cloning Module
    • The cloning module is intended to make it possible to copy up to 8 different parameter sets and subsequently load any of these onto another drive. It is useful in a production environment when many drives have to be set up with the same parameters. Unlike the other small option modules it is not normally left permanently installed in a drive.


Contact us today for an instant quote on any Control Techniques Unidrive, small option module, or large option module at 1-800-691-8511 or at


8 Standard Unidrive Macros for Uni2403 or any Classic UniDrive

Here at MRO Electric we get a lot of questions about Unidrive Macros for the legacy Classic drives. This post explains the 8 available macros for programming a Uni2403 or other Unidrive part. You can refer to the product manual for the parameters common to all of these macros. This table shows the available macros and their codes:

FaultsWhat happens when a fault occurs?
- The appropriate fault reaction is initiated
- Status signal ZSW1.3 is set.
- The fault is entered in the fault buffer.

How are faults eliminated?
- Remove the original cause of the fault
- Acknowledge the fault
AlarmsWhat happens when an alarm occurs?
- Status signal ZSW1.7 is set.
- Alarms are "Self Acknowledging" meaning they are reset when the cause of the alarm has been eliminated.

Now that you know the code for each macro, here’s a little information about how you would use each one:

Macro 1 – Easy Mode

The Easy mode macro for Unidrive classic gives the simplest operation of the drive for basic applications. It is identical to the default condition except that menu 0 has less parameters.

Macro 2 – Motorised potentiometer

The Motorised potentiometer macro enables the drive’s own internal motorised potentiometer to control the speed of the drive via digital inputs. A digital input selects between an analog speed reference and the motorised potentiometer reference.

Macro 3 – Preset frequencies / speeds

The Preset reference Unidrive macro enables the use of preset references to control the speed of the motor via digital inputs. A digital input selects between an analog speed reference and the preset references.

Macro 4 – Torque control

The Torque control macro configures the drive for use in Torque control mode, selectable via a digital input. Analog input 1 is configured for the torque reference. When in speed control analog 2 is the speed reference. When in torque control with the drive in closed loop mode analog input 2 is the speed override reference. Enabling torque mode with the drive in open loop mode will put the drive in to pure torque control. In closed loop mode the drive will be put in to torque control with speed override.

Macro 5 – PID (set-point control)

The PID control macro enables the drive’s own internal PID controller to control the speed of the motor. Analog input 1 is configured for the main speed reference, analog input 2 is the PID reference and analog input 3 is the PID feedback. A digital input selects between an analog speed reference and the PID control.

Macro 6 – Axis-limit control

The Axis limit control macro configures the drive for use with limit switches so that the drive is stopped when a position limit has been reached. The speed reference can be either unipolar or bipolar.

Macro 7 – Brake control

The brake control macro configures the drive to apply or release a mechanical brake on a motor in a crane or hoist application. The drive issues a brake release signal via a digital output when the relevant conditions are met.

Macro 8 – Digital lock / shaft orientation

^Only available in closed loop vector or servo operating modes.

Digital lock:

The drive operates as a slave in a closed loop master-slave system. The slave motor is digitally locked to the master motor.

Shaft orientation:

The motor speed is controlled in the same way as for default operation, but the motor shaft can be orientated to a specified angular position before and/or after running the motor.

Troubleshooting a Unidrive with Hardware Fault Trip Codes

Unidrive Classics are going to trip at one time or another. Refer to this list of hardware faults next time your Uni1405 is throwing a mysterious code.

HF81 – Software Error (odd address word)
HF82 – Large option module removed
HF83 – Power Board Code Failure
HF84 – Current Offset Trim Failure
HF85 – A to D failure (ES-CC step)
HF86 – Interrupt Watchdog failure
HF87 – Internal ROM check error
HF88 – Watchdog Failure
HF89 – Unused Interrupts (nmi as source)
HF90 – Stack Overflow
HF91 – Stack Underflow
HF92 – Software Error (undefined op code)
HF93 – Software Error (protection fault)
HF94 – Software Error (odd address word)
HF95 – Software Error (odd address inst.)
HF96 – Software Error (illegal ext bus)
HF97 – Level 1 Noise
HF98 – Interrupt Crash
HF99 – Level 1 Crash

A few notes on these trip codes:

  • HF trips are internal hardware faults within the drive. Powering the drive down and re-applying power could clear the fault.
  • Resetting the drive will not clear a HF trip.
  • If a HF trip occurs, the Drive Healthy relay will open to indicate this
  • The serial communications will not function during a HF trip
  • The only HF trip that can be caused by the user is a HF82 trip where a
    large option module is removed while the drive is powered up.The drive should be powered down, the module re-fitted correctly and the power reapplied to clear the trip

If you end up needing to replace your drive, MRO stocks Unidrive Classic and can offer an exchange credit for your faulty unit against the price of the new drive. Shoot us an e-mail at and we’ll send you a  quote ASAP.