GR-SYNC Motor Control Module - Frequently Asked Questions

This page is still under construction, more questions and answers will be added soon. These questions are not intended as a replacement for the controller instructions which are available here, the instructions should be read before using the device.

If you are unsure of something, please contact us.

Wired Control: The GR-SYNC is most often operated with wired switches. These can take many forms, such as push buttons or rocker switches, but the electrical operation is simple: Connecting any of the terminals D1, D2 or STOP to either a positive voltage (e.g. to the 5V or 12V terminals), OR to GND if active-LOW is set, will trigger that input. The controller inputs are default active-HIGH, but can be toggled to active-LOW in the I/O Logic menu, where it is more convenient to use ground (GND) as the input reference.

Additional terminals are available for further wired inputs, IO1, IO2 and IN1, whose function is determined via the I/O Modes menu (see instructions page 2 for a list of selectable functions for each of these inputs).

Remote Control: Optionally, a GR-RX-868A receiver module may be mounted in to the controller to allow for operation by remote control. These modules are soldered in to place to one side of the GR-SYNC circuit board and so are usually integrated upon sale if requested, rather than added later on. Wired inputs override remote inputs (e.g. a wired D1 command will override a simultaneous remote D2 command). Bear in mind the potential hazards of remote operation if incorporating this into your system (as described in the receiver instructions).

Mains AC: Most commonly the GR-SYNC is used with mains AC to DC power supplies (also called adapters or power packs). Either ones with a 12V DC output when running 12V motors (such as our own 12V 8A offering) or a 24V DC output when running 24V motors (we offer both compact 24V 4A and larger 24V 12A options). You must ensure that your power supply is appropriately sized for your load, and test to verify that you do not have unstable behaviour (such as cut-outs) during loaded operation. Bear in mind that by default the controller brakes regeneratively, meaning that energy from the motors is sent back to the power rail under braking. Depending on the nature of the system, and the deceleration rate (which is adjustable, CTRL SETTINGS > DECEL), your power supply may not be able to handle a voltage rise created during braking. If this is the case then you should consider increasing the deceleration time, reducing inertia in the system, or disabling regenerative braking (ADVANCED > REGEN) by toggling the menu item to 'OFF'. Bear in mind that disabling regenerative braking will mean that the motor(s) coast to a stop and so stopping distance will be increased with otherwise like-for-like settings. Make sure to test thoroughly if experimenting with these settings. 

Batteries: It is possible to run from a battery supply, within the 9V to 28V limits of the controller (you would need to ensure that the fully charged battery level were below 28V). Make sure that the battery is appropriate for the load currents that you expect, and factor in that the controller has a constant idle current draw which could drain the battery. As described above, if regenerative braking is enabled (which is the default setting), a system can try to deliver current back towards a connected battery, so do make sure that your battery (and any battery management hardware that may come with it) is suitable for this. 

Voltage Limits: To help ensure compatibility with different power sources the controller has adjustable settings for an upper voltage limit (CTRL SETTINGS > MAX VLT), up-to 30V, and also for a lower voltage limit (CTRL SETTINGS > MIN VLT), down to 9V. The upper limit is immediate, as soon as the voltage detection goes higher than this setting the controller will stop any active output and prevent a new output. The lower voltage limit however has a sensitivity setting (ADVANCED > VOL TIME) which is by default 1500ms, before it stops an output, meaning that the response to voltage drops may be adjusted. There is also a fixed lower voltage threshold of 8V, below which the controller will immediately stop the output, triggering Error 9 Power Failure if the output was in motion at the time that this occurred (since it's possible, with a power drop-out during motion, that position tracking was lost while the motors were still moving). 

Error messages are generated by the controller to communicate scenarios such as an overcurrent event or a loss of encoder position tracking. See instructions page 6 section B for a summary of what the 9 main error codes of the controller are and what they mean. If you are unsure of what a particular error combination means, please contact us with details of your system and what error message you are seeing.

All Gimson Robotics linear actuators with encoders, as well as the GR-EP-45ENC and GR-WM4-ENC geared motors, are able to be controlled by the GR-SYNC.

For other brand motors you should ensure that the quadrature encoder pulse frequency does not exceed 2000Hz per encoder channel, that the load current of each motor does not exceed 12A (the maximum current limit threshold per output), and you should also test carefully to verify compatibility. Furthermore, compatibility could be affected by the operation cycle that is required, as higher-duty operation (e.g. very regular back and forth operations) may lead to the controller going into an over-temperature state. 

Contact us if you are unsure about a particular combination.

Power: By default, unless a customisation has been discussed, the controller comes with a simple screw terminal connection at the end of Red and Black cables (approximately 250mm length) for the power input, for connection to a DC supply (typically a 12V or 24V one). It is very important that the supply is connected with the correct polarity, positive (+ve) to Red and negative (-ve, GND) to Black

Control: A 10-way wired connector (2.54mm pitch) is supplied with every controller, allowing access to the 10 control input and output pins. See instructions page 3 section A for a description of the function of the 10 pins. 

Motors/Actuators: Motor connection is via dual 6-pin (4.2mm pitch, 3x2) Female connectors on the side of the control board. See page 3 section A of the instructions for a diagram of the connectors. Some actuators, such as the GLA3000-N model, include the opposing Male connector on the ends of their leads by default. Contact us if you require connector leads or other wiring accessories. 

The GR-SYNC is designed primarily for the operation of two brushed DC motors (such as those in most of our linear actuators) being synchronised together, and this is the default control mode ('2CH' in the I/O Modes > 1/2CH menu). It is also possible to set it into single motor mode, to run either one motor via the Motor 1 connector or one via the Motor 2 connector (this is configured via the I/O Modes > 1/2CH menu option, where you can set either M1 or M2 to be the output). In single motor mode the controller still tracks the motor position and uses the same control inputs as the default dual motor mode.

The controller must be 'Homed' or calibrated before use. If it was previously operating then you may have experienced an error (such as losing encoder tracking) which requires the controller to be recalibrated/re-homed to resume operation. See page 5 of the instructions for a description of the Homing process.