GE Fanuc 90-30 PID to control a recycle valve

Hi guys. I work mostly with AB products and have been given the task of adding a PID block to a GE 90-30 plc to control an analog output based off of a set point and a tank level. I found a PID in the program that is running speed control based of of the same parameters and was going to try to copy that and assign new addresses as needed. Below is a copy of the logic for the existing VFD and my Recycle valve. Can anyone tell me if I'm way off base here? I have only taken the GE 3 day course and haven't got to look into GE stuff much before this.

I was trying to download to a test rack but I don't have all the right I/O cards to put into it so my logic is showing in either Program or Monitor NE for software and hardware. Tech support told me I will never get this to be equal if the project came from another controller. WTH? Is there any way to inhibit the missing modules like in RSLogix 5000 to allow me to get online?

Thanks for any insight, Now back to the manuals...

Kraken Fan #69

What you have started in the PID function block is fine.
A couple of observations and recommendations.
**There is no need for M01112 as the 90-30 has an #ALW_OFF (%S8) System bit.
** The PID function uses 40 consecutive registers so make sure none are overwritten any where else in logic.
** DO NOT assume that anything will work like RS, just learn what tools you have available then how to use the ones you need.

When you go to tune (there is no auto-tune unless you have the "Process" version of PME called PPS) it, Right-Click the PID Function Block and select "Tuning...".
The online help has very good explanations and examples, to find them select the PID function block in logic and press "F1".

Additional info:
To make the hardware configuration "Equal" is not needed to have Logic "Equal" and RUN it. You may need to clear "Faults" before it will go into RUN though.
But it sometimes makes sense to clone your project then change the hardware config to match your test bench setup.
Then you can download all without issue.
As to the CPU being different, the only place you may run into a problem there is if your bench CPU does not support the same number of %AI, %AQ or %R addresses. Of course it will trigger Config Not Equal and necessitate clearing the fault to get into RUN.

Generic questions prompt generic answers.

Thanks for the heads up. I'm not really looking forward to this little project not working in GE before but your reply helps calm the nerves a bit to hear I'm not too far off track anyway!


Kraken Fan #69