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Keep Rebooting PLC
Operators keep rebooting PLC (Siemens Gas Compressor) to make alarms disappear

Operators facing some alarms during running of Siemens Gas Compressor. Alarms stayed appeared, so operators always waiting for compressor Shutdown and reboot PLC to make them disappear.

Actually we are investigation about those alarms.

My Question is:

Does rebooting PLC many times affects it?

Thanks & Regards

1 out of 1 members thought this post was helpful...

It will not hurt the PLC.

thanks so much!

By Bob Peterson on 22 February, 2018 - 9:46 am
1 out of 1 members thought this post was helpful...

It probably won't hurt the plc but it isn't a good solution. There should be some way to reset the alarms without having to cycle power on the PLC.

Thanks Bob, we will check that.

1 out of 1 members thought this post was helpful...

If you are cycling the PLC power to clear the alarms and reboot the PLC, you may be reducing the reliability of the PLC. This is because cycling causes the PLC to power up, which is a stressful time for any electrical/electronic device. Repeated starts up will stress the PLC.

Also, since cycling the PLC clears any non-retentive registers, which may be why it clears the alarms, I would look at your registers to see if the value or bits in one of the registers are preventing the PLC from clearing the alarms. I would also look in the program where the alarm reset button is located and see what conditions are required to reset the alarm (e.g. alarm condition to clear, etc.).

There may also be a means to restart the program without cycling the PLC. Look in the application program and the programming manual.

Last but not least, read the system manual to see if there is a clue as to why your program is doing what it is doing.


William (Bill) L. Mostia, Jr. PE
ISA Fellow, FS Eng. (TUV Rheinland)
WLM Engineering Co.

It is really helpful, I'll check with that.

thanks a lot William.