GE Fanuc T coils in VersaPro

Does anyone have experience with using multiple T coils in VersaPro? I have seen it done in Logicmaster with an alarm circuit.

I have several T coils in my program, but the only one that will be highlighted when it is "ON" is the last one in the ladder. The others will not be shown as on, even if the conditions in that rung are true to make the coil turn ON. The other weird thing is that I made the conditions true for one of the coils and it did not look like it was ON, but the rung below it where I had a normally open contact would energize that rung even though the contact did not show as ON. This was inconsistent in the whole ladder, the rungs did not function as they should have.

Is there an issue with using multiple T coils in VersaPro. I am using VP professional v2.02.

I can rewrite the logic using different coils then have all of the normally open contacts of those energize another coil, but using one coil was going to be easier.

Thanks
Dave

T addresses behave just like any other address when you use multiple coils. What shows up on your PC's screen is the status of the coil at the end of the program scan, not the conditions that existed at the time the rung was evaluated.

The easiest way to avoid confusion is to avoid using the same address more than once for any coil instruction.

I can rewrite the logic using different coils then have all of the normally open contacts of those energize another coil, but using one coil was going to be easier. I can rewrite the logic using different coils then have all of the normally open contacts of those energize another coil, but using one coil was going to be easier.

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Even if you could work out a way to do what you want with only a single coil address, it wouldn't necessarily be easier. Furthermore, would you be able to troubleshoot it six months from now? They don't give out any prizes to the person who uses the fewest addresses, and the PLC generally has plenty of memory.

When writing ladder logic, it's generally better to emulate Ernest Hemmingway than James Joyce.

Dave Powers said:

I have several T coils in my program, but the only one that will be highlighted when it is "ON" is the last one in the ladder. The others will not be shown as on, even if the conditions in that rung are true to make the coil turn ON. The other weird thing is that I made the conditions true for one of the coils and it did not look like it was ON, but the rung below it where I had a normally open contact would energize that rung even though the contact did not show as ON.
Dave

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You have discovered the intended operation of the discrete coil in any 90-30 or VersaMax PLC.
Now that you know how they work you can use this to your advantage, but you must be careful.
This is why it is 'normaly' advised to not use the same coil address more than one time.
The %T is a 'temporary' coil designed to be used by several rungs and then it can be reused by several more, it is a 'Temporary' binary 'scratch pad'. You have described very well how this acts. You should use 'Different' address for each coil that you want to be used by all logic, then the %T acts just like the %M, except it cannot be made retentative.
You may be able to use the 'Continuation' Coil -(+)- and Contact -|+|-combination to make a 'virtual' long rung.

Thanks for the help.

Makes sense now. I will rewrite my logic. I had seen this done in our ECM area and it looked like it would work well, but you are right with the troubleshooting aspect. The people looking at the logic would not be very happy with me.Lesson well learned.

Dave