PID configuration in RSlogix 5000 version 16

Dear All,

I want to develop a logic for a control valve. So i am using PID instruction in ladder logic, but i am not getting any output (%).
Can anybody send me a PID settings. So that i can check my ladder program.

Regards,
Manasee

Have a look to the link below; it is an example of PID in RS5000 ladder.

LINK - ROCKWELL KB

Hope this helps....

- [font=comic sans ms,sans-serif]fuzzy logic[/font]

you might also post your existing program ... we'll be glad to take a look at it for you ...

PID ladder logic

Thanks for your valuable replies

Here i am attaching my ladder logic for PID controller. Pls advise / suggest on the faults in pid instruction setting if any.

Regards
Manasi

attachemnt for prev reply

pls see the file attached

-Manasi

Greetings Manasee ...

I'm sorry but I only have a few seconds available to look over your program ... if I have more time soon I'll try to take another look ...

in the meantime I suggest that you double-check the settings on the PID's "Scaling" tab ... the values that you have there are not typical for a CompactLogix system ...

also, please read up on how the PID rung should be conditioned with a "False-to-True" transition to "trigger" the PID into executing at a specific time interval ... (coordinate this with the "Loop Update Time" setting ... from what I have had time to dig into so far, your PID rung appears to be constantly true (except for that XIO instruction) ... another (possibly better) "triggering" approach is to put the PID on an unconditional rung within a Periodic Task ... by improperly executing it on every scan (as apparently you are) both your Integral and Derivative actions will be GROSSLY out of adjustment ...

the XIO for the .MO bit should be removed ... putting the PID into (or out of) automatic mode should not be done by disabling the PID ... basic idea: let it continue to execute - but set the internal control bits (ex: .MO) to set the desired mode ...

I hope this helps ... I wish I had more time - but I'm swamped right now ... I'm sure that the other forum members will be able to help with your project ...

Thanks, i will try out with your suggestions.

Regards,
Manasee

As Ron already mentioned you scaling seems to be off. The control variable is scaled from 0 to 0.