Brand New PLC Learner

Hello everybody I am new to the site and new to PLC programming.


I would like to know a couple of questions. I am using a function block flow task template on RSlogix5000 v.20.04

first I made my PIDE work but when i change the set point higher than the PV the CV goes way down and after a good amount of time it slowly goes up and if i increase the PV higher it sinks again. is like it seems my PV ramping up and CV closes but i would like to not act so far ahead cuz is so far from the SP.

sp=80 PV=40

also i want to characterize a table of x and y values to produce a curve and the output it to an air damper, which block does that? is that under the math section? I have browsed through all the options I cant seem to find the magic block with a blank x and y table.

if you could send me some files with PIDE working and characterization would be much appreciated!! thank you!

For the first part of your question: you need to try different values of P, I and D and see which work best (PID tuning).

For the second part: not sure exactly what you are trying to do but I would look into the CPT or FGEN instructions.

Yes, I see. I found the FGEN block to be the one i am looking for. I just dont know how to take any input into X1 which could be anywhere from (0-100%)
and then output something from 0-100%.

I want to characterize a flow signal. does anybody can give me an example? on how to make the block work? i get a big red X in a circle on my block. Thank you!

androcci said:

Yes, I see. I found the FGEN block to be the one i am looking for. I just dont know how to take any input into X1 which could be anywhere from (0-100%)
and then output something from 0-100%.

I want to characterize a flow signal. does anybody can give me an example? on how to make the block work? i get a big red X in a circle on my block. Thank you!

Click to expand...

I got rid of the crossed red circle by making REAL[11] for x1 and y1. i have enabled in and out. i have an analog flow coming in but nothing coming out

I changed instructFault, XY1sizeInv, XY2SizeInv to zero

androcci said:

I got rid of the crossed red circle by making REAL[11] for x1 and y1. i have enabled in and out. i have an analog flow coming in but nothing coming out

I changed instructFault, XY1sizeInv, XY2SizeInv to zero

Click to expand...

i got it working!!. i didnt know that XY size was at 0 and it is suppose to be the sam size of the array which in my case is 11. Thank you anyways!!