PLC Recommendation For PID Control?

Hello All,

I have a client that is in need of a PID controller for a water pressure application. He requires this controller to be integrated within an existing system to control pressure of a hot water system.

He needs to control a variable frequency drive using an analogue output (4-20mA speed control).

Therefore I think that I need a PLC with maybe 8 - 10 digital inputs and outputs (for drive signals etc), 1 analogue input (from the pressure sensor) and 1 analogue output (to the variable speed drive) to be sure of covering all eventualities.

Also I need the ability to change the system set points and PID variables from an operator interface, HMI etc.

Therefore could anyone recommend a solution to achieve the above?
If so what PLC or HMI manufacturers would you advise.

I do prefer Allen Bradley and from what I can gather the MicroLogix 1200 along with a small text display could make this possible but please offer your suggestions.

Thanks

Not sure if you even need a PLC. Depening on the scope of you project the VFD will most likley do a PID all on its own. If a PLC/HMI is needed due to the size of project then you are on the right track. I wouldn't recommend an AB screen though. They are way to expensive and are limited. ProFace screens are nice.

If you want A-B, then the MicroLogix 1200 will do the trick nicely, and it has PID control. I'd agree with Beryl and stay away from the PanelView - the old ones are over priced and the PanelView Plus isn't quite ready for prime time yet.

I've had good luck with the AutomationDirect.com EZTouch with the ML-1200. (While you are at it, take a look at their DL-06 PLC)

Thanks Guys for your suggestions.
Because I'm in the UK I will have to go through the UK partner of Automation Direct but still the prices appear lower than Allen-Bradley especially for the HMIs. Will still consider using a MicroLogix 1200 though.

Thanks again.

I have to agree with Tom. The new DL-06 PLC really rocks. It has the same proccessing power of the DL-260 and only cost $215! It is not super expandable but for small apps works great.

I would recomend you to use AB too But you may use Omron CPM2
You can have 2 rs232 ports 1/256 or 1/6000 analog card and PID.
you cane use NT2S HMI(very cheap $200 here).
Another bnifits online edit,you can be connected to the PLC when the HMI connected too. the processor is powerful like CQM1 family.
It much cheaper then AB.
If you need floating point AB is the right choice.NT2S work with AB too.