adccommunitymod (AutomationDirect) asked a question.
I/O alarm
Created Date: November 20,2004
Created By: e riley
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I am using a 450 plc with 5 remote units. About once or twice a week, I get a remote I/O alarm from remote #3. I have replaced the remote slave unit, backplane, external 24vdc power supply, and a 24vdc input card in this remote panel. The only cards in this rack are 1-24vdc input card, and 2- 100vac output cards. The remote slave has an internal 24vdc power supply, but it was not used for some reason. Any help would be appreciated.
Created Date: November 20,2004
Created by: e riley
I am using a 450 plc with 5 remote units. About once or twice a week, I get a remote I/O alarm from remote #3. I have replaced the remote slave unit, backplane, external 24vdc power supply, and a 24vdc input card in this remote panel. The only cards in this rack are 1-24vdc input card, and 2- 100vac output cards. The remote slave has an internal 24vdc power supply, but it was not used for some reason. Any help would be appreciated.
Created Date: November 22,2004
Created by: Tech Guy
The two most likely suspects are noise and power spikes.
Either one has the power to disrupt communications long enough to give you the error.
If you do not have surge suppression on your incoming power, I suggest getting a TVSS unit and putting it just before the incoming power to the PLC. Remember that if you have anything else powered off of the output of the TVSS unit, the other devices could be the ones causing the noise or spiking.