PID GAP Control

[DavidYi]

New in PLC programming, how is PID Gap Level Control configured in a RSLogix5000 program?

 

[TWS]

read this:http://literature.rockwellautomation.com/idc/groups/literature/documents/wp/logix-wp008_-en-p.pdf.

 

[Mickey]

Can you clarify the term "Gap Control"? ( on-off or dead band)

http://www.cotoz.com/2012/05/21/what-is-the-gap-controller/

 

[DavidYi]

PID Gap Level Control

Function block is not to be used, need to configure in ladder logic format.

 

[DavidYi]

Dead band or On/Off fine but dead band could be logical choice.

 

[Mickey]

A little more clarification would help someone help you.

Maybe describe the process. Is this just on-off control? (don't need a PID control for this)

Or is this a PID control with a dead band ( where the controller does nothing until out side the dead band)

Is this homework?

What senses the level? ( switches or analog)

 

[DavidYi]

PID control with dead band, output of this level controller is used to adjust speed of pumps. If level of tank is within the gap pump is to maintain speed and if level is above or below pump speed needs to increase on above and decrease on below the gap. The backup pump will needs increase speed if running pump speed is at max or pump trips.

 

[Mickey]

I am not a RSLogix5000 user, but I'm sure those that are will be along soon.

Most PID instructions have a deadband setting, see excerpt from the RSLogix5000 instruction manual.