Strange Micrologix Output Behavior

[OmniKurt]

I've got a Micrologix 1200 that I'm trying to use as a controller for a clock display. I was trying to light up a seven segment display showing tenths of a second, using 7 of the relay outputs. I made a simple program with 10 timers, each one being triggered off of the previous one completing. As each timer is timing, the respective outputs are energized for the correct digit.

The program seems to be working, but the outputs don't respond as expected. I can see the timer contacts energizing, but the outputs only respond on one of the rungs. Could this be because some of the same outputs are asociated with several of the timers?

Or is the PLC defective?

 

[rsdoran]

Not sure exactly what you have done but using outputs in multiple rungs is a no-no.

Also note that plc timers are not precisely accurate.

 

[bernie_carlton]

Yes, the problem is that an output occurs more than once. The state of the last rung which controls an output sets its final state.

Delete the outputs as they now exist. Add seven rungs. Each one has exactly one of the segments as its output (OTE). Have as parallel contacts the state oa any timer which reguires that segment.

 

[OmniKurt]

Thank you both for your advice. As I was thinking about the problem and typing the question, I sort of figured that the multiple outputs was a bad idea. Your suggestions make perfect sense, and will be implemented.
Thank you!