The most common reason for this event is a peak in electromagnetic (EMF) 'noise'. This may result from contactors, power relays, solenoid valves, etc. switching on and off, as well as from power transformers and motor speed drivers.
Recommendations
Use different power supplies - highly recommended - one for the controller (CPU and inputs), and a different one for other electromagnetic devices;
Use suppressors - reverse connected diodes for DC loads and RC filters for AC loads;
Where possible, place the signal cables, including the 24V power supply, far away from power lines, especially from cables, coming in and out of motor drivers;
If needed, use shielded cables for signals, including for 24 VDC and for power cables between the motor driver and the motor itself.
Taking these precautions should help prevent ' Controller Restart'. If the problem persists, contact
support@unitronics or your local Unitronics representative.