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

[wendaiyu]

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.

 

[JeremyM]

No. Neither a relay, nor its card, can sense the thrown load.

Check the logic governing the output.

 

[padees]

Is the output being stepped on by another recurrence of the output in the PGM?

 

[Mickey]

Check the logic governing the output.

I agree, it sounds like a logic issue

Is the output being stepped on by another recurrence of the output in the PGM?.

(double coiling?)

If you can't find it post the code (I.D the output for the forum) Zip the file first.

 

[padees]

I agree, it sounds like a logic issue

(double coiling?)

If you can't find it post the code (I.D the output for the forum) Zip the file first.

Sorry Mickey, I learned the "stepped on slang" to indicate a double coil.

See if that's it.

 

[bernie_carlton]

'stepped on' is perfectly fine in this case. I first heard it used in an electrical sense in amateur radio when two transmitters used the same frequency at the same time, leading to a mess equivalent to this (if the 'double coil' operation is the case.)

 

[nehpets]

With the SLC range and with a lot of other PLC's with a double or multiple coils with the same reference the logic would take the status of the last operation on that coil (ie not turning the output on (or off)when it should do), but as you have found due to the asynchrony of the i/o of the controllogix range the result is a rapidily flashing output, given that the issue is a double coil.

Steve

 

[James Mcquade]

wendaiyu,

What we are trying to say can be put like this.

let's say you have a program of 100 rungs and maybe some subroutines.

in rung 5 of your program you turn on an output (out1).

in rung 75, you turn the output off using an internal bit (bit1)contact.

As with all programmers, you must learn.
look at your code and search for multiple outputs of out1. if rung 5 turns it on and in rung 75 you have it programmed as well and it's off, the output will do as you say. you can also go online and look at the output rung and see what's turning the rung on and off.

regards,
james