ECC Forum

I thought I was getting a grip on ladder logic, but this latest has me confounded. I am running a BCS-482 with latest firmware 4.1.3 build fd86a103. Rungs are as follows: Take a look at rungs 14 and 15. Din0 NO box is green on rung 14. Din0 NC box is not green on rung 15, as we would expect. But take a look at rung 14 Out7 NO box is green, yet rung 15 Out7 NC box is ALSO green?? What am I missing here? This is turning on my Out7 when it shouldn't be. I'm trying to make it so when Din0 is not on, Out7 is also not on as an interlock.

Any help, guidance, suggestions, laughing at my silly mistake (but pointing it out), or the like is much appreciated!

Said / shown another way: Why is Out7 outputing 12V when Din0 is receiving 12V? I’m trying to make Out7 stop outputing 12V if Din0 stops receiving 12V.

Move the contents of rung 15 to 16 and then clear 15 to see if it makes a difference.

Here is the change suggested, but it still shows the same behavior. I also tried moving that line to rung 11 with the same result.

It is as if the coils are acting like contacts...

I ended up moving the suspect rung to rung 0 and now it works as expected. Go figure.