Cannot energize the output from Relay output module (1769-OW16) without the load?

[wendaiyu 0]

Hi, guys, how’s going?

 

We made a very simple logic in Logix5000 and turned on one output from Relay output module (1769-OW16) WITHOUT the load.

 

But the issue was that the indicator of that output was blinking and its relay was closed, open, closed, open….

 

It looks like we cannot energize Relay output without the load, right?

Thanks a lot.

[JRoss 84]

No, load doesn't make a difference. If you turn the output on in software, the output should come on and stay on, and the relay should close and stay closed. The most likely cause is a programming issue, so do a cross-reference of the output address and see how many times it's written to, and make sure they don't conflict. Note that direct coil (OTE) instructions are written every scan, either off or on depending on the rest of the rung, while latching coils (OTL and OTU) are only written while the rung is true.

I suppose there's a possibility of a hardware error (bad module, power fluctuations, etc.), but it the system was working properly before the program change, then the program is the most likely problem.

[Jay Anthony 118]

Good call, JRoss!