Intermittent Output

Prayder · Sep 25, 2018

I have a 24VDC output wired up to a 24VDC Ice Cube relay. 24VDC + to pin 2 and 24VDC - to pin 7 of the relay. So when i toggle the outputs in the program they turn on and then off even though everything in the rung before the outputs stays on. They continually turn on/off in the program. On the physical card in the chassis the output stays lit up and doesnt drop out but I have no voltage on the outputs...

Any ideas?

PLC Pie Guy · Sep 25, 2018

Prayder said:
I have a 24VDC output wired up to a 24VDC Ice Cube relay. 24VDC + to pin 2 and 24VDC - to pin 7 of the relay. So when i toggle the outputs in the program they turn on and then off even though everything in the rung before the outputs stays on. They continually turn on/off in the program. On the physical card in the chassis the output stays lit up and doesnt drop out but I have no voltage on the outputs...

Any ideas?

You have A relay connected. You are toggling outputS.
How many uses of this output address is in your program?? Most importantly, how many times is this address mapped to an output instruction?

You can post a screen shot of your logic for constructive criticism from others.

Prayder · Sep 25, 2018

I realized the output was in 2 separate places and even though there was an AFI at the beginning of the second output rung... it was dropping out...

Thank you for pointing that out....

proof · Sep 25, 2018

Prayder said:
even though there was an AFI at the beginning of the second output rung... it was dropping out...

An AFI is an Always False Rung. It does not a don't scan and execute the rest of the rung and leave outputs the same command. It evaluates as false, and the rest of the logic gets executed. At times it would be nice if there was a don't scan the rest of the rung and change outputs command, but I'm sure it would get abused in ugly ways.

alive15 · Sep 25, 2018

I generally create a dint and title it "always off" or "always on" and use the 32 bits for testing purposes, in case I ever need to toggle outputs on or off

Intermittent Output

Prayder

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proof

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