Category Archives: Unidrive SP

Emerson Industrial Automation Unidrive SP

Emerson Industrial Automation: Unidrive SP Troubleshooting

Emerson Industrial Automation: Unidrive SP Troubleshooting

Updated August 2019: Click here to view Unidrive fault codes.


The Unidrive SP can be enabled to run in several ways. The drive can use digital inputs, keypad, or a field buss networks to give the OK to run. The drive will display inh, rdy, or run depending on the given commands. The drive can be programmed to use positive or negative logic. The logic type is set up at #8.29 in the Control Techniques Unidrive SP. The Unidrive SP defaults to positive logic. When the drive is in positive logic you will need to inject +24VDC to activate the digital inputs. The +24VDC can be supplied by the drive or externally.

The Unidrive SP can be enabled to run in numerous ways.

When the drive is in the terminal mode the following sequence occurs under default conditions:

Unidrive SP:

Inh = Drive disabled = Connect pins 22-31 drive should go to rdy
Rdy = Drive enabled = Connect pins 22-26 drive should go to run
Run = Drive is enabled and ready to run when a speed reference is applied

Parameter #0.05 sets up the Reference Select. This will tell the drive where to search for run commands and speed references. You will only need to close the enable signal if it is set to pad. Then, the keypad can be used to control the drive and to set the speed reference. The speed reference will come in on an analog input if you choose a terminal code. The digital inputs will select the enable, run, and preset selections. The drive should operate as seen above if the digital inputs are activated correctly.


When the drive is not running, there are several additional parameters in menu 6 that can assess the issue. The digital inputs may be configured wrong or inactive if the parameters are not going to a 1 with the corresponding commands. Check the following parameters:

#6.15 = 1 = Drive enabled

#6.43 = 1 = Control word disabled, Set to 1 for Field Buss Control

#6.29 = 1 = Hardware Enable (Pin 31 is activated)

#6.30 = 1 = Run Forward #6.31 = 1 = Jog

#6.32 = 1 = Run Reverse

#6.33 = 1 = Forward/Reverse

#6.34 = 1 = Run

#6.37 = 1 = Jog Reverse

#6.39 = 1 = Not Stop

Unidrive SP

The voltage on the corresponding digital inputs should be measured if the parameters in menu 6 aren’t changing state accordingly. The DC voltage should change between 0VDC and 24VDC when a command is given. Check the digital input configuration in menu 8 if menu 6 isn’t changing and the voltage is.


To control the start/stop functions, the drive does not have to use the digital inputs. When #6.43 = 1 the control word is enabled. The drive will now accept a decimal value from 0 to 32767 at #6.42. This decimal value can be converted to a binary value.To see the function that will be carried out, you can reference the binary value to the chart below.

Unidrive SP

Speed Reference

The drive still may not run if the digital inputs and the drive sequencer are each working properly. There could be an issue with the speed reference to the drive if the display shows Run but the motor isn’t turning. The speed reference is able to be applied in several methods. An analog input can be used (current or voltage), preset speeds, and a field buss reference. The example is a 0-10VDC signal on analog input #1.

The final speed of the demand is parameter #3.01. The speed reference should be displayed here if the digital inputs and the drive sequencer are failing to operate properly. Check menu 1 and 2 to determine where it is stopping if the reference is not getting to this point.

If the drive is running in torque mode, the torque reference will come on parameter #4.08 under default conditions. #4.08 is able to be linked to an analog input or be written to via a filed buss network.

Unidrive SP

#7.01 should be inspected to determine if it changes with the change in reference at terminal 5 once the signal has been confirmed. #7.01 goes from +/- 0% – 100%. Check the destination of the speed reference at #7.10 if everything looks good. Follow it to the destination and confirm the speed reference value is arriving there and then through #3.01.

Unidrive SP

Contact the America’s Service Center if the drive will still not run after the Speed Reference, Digital Inputs and Drive Sequencer have all been confirmed.

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

Unidrive SP SM-EZ Motion HF Trips

Unidrive SP SM-EZ Motion HF Trips

This guide is meant to help clear SM-EZ Motion HF Trips on a Unidrive SP drive from Emerson Control Techniques. The SM-EZ motion module is used with SP drives and is programmed using Power Tools Pro. It allows users to create specific motion profiles such as indexing, home routines, electronic gearing, and many others.

An HF (hardware fault) can be generated by the drive if there is a problem with the solutions module. The drive will display the trip as SLX.HF. It is sometimes possible to correct this trip without replacing the module. The EZ Motion program in the module may become corrupt which can cause this type of trip. Clearing the program and setting the module back to factory settings may resolve the trip. Before clearing the module a drive reset and power cycle should be performed.

They could correct the trip as well.

unidrive sp
Module Clearing Procedure

1. Ensure the module is installed in any slot

2. Enter 19237 at #18.01

3. Cycle power to the drive

4. The drive will trip SLX.ER on power up. This is a 107 “No Program” trip

5. Press the red reset button to clear the SLX.ER trip

6. Reload your EZ Motion program back into the drive.

The HF trip could be resolved at this point.

MRO Electric supplies and repairs a large number of Control Techniques Unidrive SP parts. To request a quote, please call 800-691-8511 or email

Unidrive SP AC Drives Used in Belgian Theme Park Ride

Unidrive SP AC Drives Used in Belgian Theme Park Ride

Wondering what Control Techniques Unidrive SP Drives are actually used for? Well here’s a pretty cool application for those of you that enjoy theme parks. This zero-gravity ride at the Walibi Theme Park in Belgium was recently refurbished using Unidrive SP Drives. Previously, the ride had been using Unidrive Classic Drives to run the motors which hoisted riders over 250 feet in the air.

emerson drives on rides
Dalton Terror Ride powered by Unidrive SP Drives

More information about the retrofit:

The drop tower is based at the Walibi theme park; the ride is a round tower of 77m in height and has five rows of seats, each with four-person capacity, in a ring around the tower.

The seats, weighing 1.5 tonnes empty, are hoisted by speed-controlled Leroy Somer geared motors to the top of the tower, where they are released to drop in freefall at a maximum speed of 110km/hr, generating complete weightlessness.

Magnetic current brakes that comprise permanent magnets fitted in the seats generating powerful Foucault currents in the metallic frame of the tower provide fault-free guaranteed braking, independent of the power supply, bringing the ride to a safe slow speed with hydraulic shock absorbers providing the final soft stop at the base.

This, Control Techniques said, makes the ride a ’zero-risk’ attraction.

The Dalton Terror was originally installed in the park in 1998 and featured the previous Classic Unidrives to haul the seats to the top of the tower.

Compagnie des Alpes has been investing heavily in the upgrading of many of the rides, with the accent heavily on safety.

When it decided to refurbish the Dalton Terror, the precise movement of speed profile of the previous Control Techniques drives was a key factor in the selection of the latest-generation of AC drives and five heavy-duty 75kW Unidrive SPs, operating in closed-loop flux vector mode, were fitted as part of the total renewal of the control panels.

Signals from encoders fitted to each of the Leroy Somer LSMV motors feed back to the drives and, using SM Universal Encoder Plus option modules, are re-transmitted to the PLCs that control the safety of the whole process.

Here’s a video of the ride in action:

MRO Electric and Supply has new and refurbished Control Techniques parts available including the Unidrive and Unidrive SP series. We also offer repair pricing. For more information, please call 800-691-8511 or email