Help with PIDE in rslogix 5000

Hi all, I am playing around with a couple of things and need some help with the PIDE function block.

I am trying to get a constant level in a tank, as product is drawn out product flows in the faster it flows out the faster it flows in..Perfect for a PID loop.

I have a pressure sensor reading the level in the tank (Engineer units 0-20) and a I/P transducer on the output (0-60psi). Now i am just trying to make it work at the moment..It doesn't have to be pretty.I plan to read Ron B's PID tutorial to tweak and tune it but i just cant figure it out..

The level set point will be made by the operator on a PV+

Any suggestions to get me going?

Specifically i am wondering what node do i put the operator's set point in, what node should the output go on and how do scale?

Not asking for much am i..

BTW i am complete noob at PID if you didn't realise and this at the moment is just for info purposes, Don't actually have an application but do have the toys to play with!

Thanks

Darren

Start with Ron's tutorials.

For PIDE tutorial look at G9057916 - Logix PIDE Function Block Information

http://domino.automation.rockwell.com/applications/kb/RAKB.nsf/0/4E8D5815D1D6C19785256BB9006E4857?OpenDocument

Make sure PIDE is on periodic task with update rate equal to the loop update time.
Set point in Operator mode SPOper, in Program mode SPProg
PIDE scaled output is always CVEU

PID should be a perodic task?
how do i scale the output? or does it do it automatically?

darrenj said:

PID should be a perodic task?
how do i scale the output? or does it do it automatically?

Click to expand...

PID MUST(!!!!) be triggred by timer or used in periodic task.
PIDE MUST be in the periodic task.
Output Scaling is in CVEUMAX(100%) and CVEUMIN(0%)

If 1756 analog outputs used, then you can scale it in the module.

G9057916 - Logix PIDE Function Block Information

Contr_Conn:

I looked for Ron's tutorials but RA requires me to have Techconnect access level. is this the Only link to reach for Ron's tutorials?

Ron's tutorials are at link below. They are not part of Rockwell's Knowledgebase.

http://www.ronbeaufort.com/sample_lessons.htm

And more links on the subject.

http://www.google.com/url?sa=t&sour...pNmrDg&usg=AFQjCNGl3DDvJnUq-HDVj4B7_wYDcghf5Q

http://www.google.com/search?rlz=1C....,cf.osb&fp=ebaa3ff8b466872e&biw=1593&bih=807

if you're interested in how to set the "Control States" and the "Operation Modes" for a PIDE instruction, then the following link might be helpful ...

http://forums.mrplc.com/index.php?showtopic=14562&view=findpost&p=71278

the PDF files in the first two or three posts demonstrate the "what comes in - and what goes out" ideas for various types of operation ...