S
Hi,
Normally i am using single output to start and stop a motor from PLC. When the relay is energized, the motor starts, when the relay deenergized, the motor stops.
But my customer requested 2 DO (start and stop) to control motors. And it should be momentary. I used NO contact of relay for Start, and NC contact of relay to stop. So the 1-2 second pulses can start and stop the motor.
The problem is, if the PLC or the relays fail, the motor can not be stopped and keeps running.
I am thinking to use NO contact for Stop relay too, but then it will not be momentary.
Any comments?
Thank you,
Normally i am using single output to start and stop a motor from PLC. When the relay is energized, the motor starts, when the relay deenergized, the motor stops.
But my customer requested 2 DO (start and stop) to control motors. And it should be momentary. I used NO contact of relay for Start, and NC contact of relay to stop. So the 1-2 second pulses can start and stop the motor.
The problem is, if the PLC or the relays fail, the motor can not be stopped and keeps running.
I am thinking to use NO contact for Stop relay too, but then it will not be momentary.
Any comments?
Thank you,