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Is it possible to forbid negative velocity moves?
We have a motor on an axis driving a pump which must not be driven in reverse. Is there any motor setting that can be used to ensure this?
Depending on your hardware, you might want to consider doing this at the drive level.

Or maybe putting a diode or something similar in the torque command wiring (if analog)

Another approach might be to write a plc which monitors the motor's PID torque request, and clamp the Motor[*].maxdac value or perhaps the Motor[*].Servo.MaxPosErr value if it goes negative and set an error flag. This could have some issues with decel, though.
To prevent the possibility of a commanded move in the negative direction, you may want to have a PLC program continually set Motor[x].MinPos just slightly less than the present position (Motor[x].ActPos - Motor[x].HomePos). Set Motor[x].MaxPos to a huge positive value.

For protection at a different stage, you may want to monitor Motor[x].ActVel, and if it is negative for several consecutive scans, disable the motor.
You may also want to look at Motor[x].DesPos and DesVel to see the commanded velocity.

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