Should a PLC have its own dedicated power supply or can I connect it to the same bus as my 24V servomotor?
Typically, it is advisable to have a PLC, even if it is a programmable logic controller, on an independently fed power supply and not on the same bus as your 24V servomotor.
Here are some reasons why: Servomotors tend to generate electrical noise, particularly when in operation, and voltage spikes. This noise can cause interference in the operation of a PLC, which may manifest as erratic responses, miscommunication, or sometimes even damage to the PLC.
Power Quality: The power demand of a servomotor may vary, thus leading to voltage sag or swell on the shared bus. A PLC requires a clean and stable power supply for its proper operation, while any fluctuation in this power supply will lead to system instability or an unexpected reset.
Isolation: A dedicated power supply for PLC makes it electrically isolated from other high-power or noisy devices. This isolation protects the PLC and ensures more consistent operation. Troubleshooting: It’s made to be easily troubleshooted in case something goes awry. You could very well easily identify if the problem was with the motor, power supply, or if it was an issue with the PLC. while it might be possible to connect both to the same bus, it’s safer and more reliable to provide the PLC with its own dedicated power supply.