Temperature Controller with data logging.

[Elcan]

Hi all,
Do you know if exists such thing of a temperature controller with data logging capabilities?
I need to open/close a valve according to a temperature value, and I would like to keep track of the temperature values during the last hour. I don't want to use a PLC in this case.
If such controller does not exist, what are your preferred alternatives?

Thank you very much!

 

[TheStarr]

This may be too simple, and it does not data log but...

A normal home HVAC thermostat does exactly what your asking. It opens and closes a circuit based on temperature (which could drive a relay controlling a valve).

Maybe you could use an external data logger.

A little more info on the system your installing it on and requirements (example: air or liquid valve?, what will read temperature?, must be industrial quality?, intreniscally safe?, washdown rated?, or only temporary?, etc) would help.

 

[Peter Nachtwey]

Gross Overkill

I know of a PID controller that can log over 12000000 32 bit values. That would be enough for 145 days. If you want you can log the SP, PV, CO and Status but then the number of days is only 145/4 is only 36 days. The nice thing is that you can scroll back 36 days in trend mode.

 

[Elcan]

A little more info on the system your installing it on and requirements (example: air or liquid valve?, what will read temperature?, must be industrial quality?, intreniscally safe?, washdown rated?, or only temporary?, etc) would help.

Thank you for your response. It's a liquid valve in an industrial environment. There will be an industrial temperature transmitter.

 

[Elcan]

Peter,
Could you give me a link for that controller?

Thank you!

 

[Joe_WaZoo]

Like Peter said, I too know of a PID controller that can log the data as well. I don't know it if will do quite as many values as Peter's can, but still do a fair share. Here is what I thinking of:

http://www.redlion.net/Products/Pro...ller/ModularControllerSlaveModules/CSPID.html

Thanks,
Joe_WaZoo

 

[Elcan]

Actually I was thinking about a device where I can access the stored values directly. I should have specified this requirement from the beginning...

 

[Joe_WaZoo]

With a Compact Flash card and use of the CSMSTRSX model Modular controller you could access all of the data log values right on the device via a USB cable or an Ethernet connection to it. No need for a PC to be logging the values, the Modular Controller will handle all of that.

 

[Peter Nachtwey]

I said it is gross overkill but maybe not.

http://www.deltamotion.com/products/motion/rmc70/index.php
If you look at the picture all you would need is the CPU and axis module. It is small.

The RMC75E AA1 is actually a motion controller but it has been used to control temperature too. Usually there are cheaper options but it does what you want to do.

If you really need only one hours with of data then the RMC75S AA1 is a little cheaper because is has serial ports instead of USB and EThernet. It can store 32768 data points which is far less but still more than 9 hours at 1 sample a second.

It supports many different PLC protocols so you can hook it up to most HMIs, PLCs, PC and data acquisition and analysis system such as LabView.

Is there feed back for the valve or does it run open loop. If so we can do a cascaded loop too. This may be handy because usually temperature control systems with valves have a dead time proportional to the volume/flow between the valve and the temperature sensor. The controller is programmable so it can adjust to the varying conditions without outside intervention.

 

[Elcan]

What I'm looking for seems to be like a paperless recorder and loop controller at the same time, like if the device on the link below were also a loop controller.
http://www.microdaq.com/monarch/paperless_chart_recorders/datachart1250_recorder.php

 

[Elcan]

I found it! I don't know how expensive it is, though.
http://www.yokogawa.com/ns/daq/cx/daq-cx_01.htm

 

[Bill Wheeler]

Yokogawa has a very nice line and I haven't found them to be over priced considering what you get.

 

[danw]

The West ProVU4 single loop PID controller has an option for on-board data storage, exactly like you are asking for.

http://www.westinstruments.com/uploadedFiles/Downloads/ProVU datasheet 0408 V2.pdf

DATA RECORDER
Recording Memory:
- 1Mb non-volatile flash memory. Data retained when power is turned off.
Recording Interval:
- 1; 2; 5; 10; 15; 30 seconds or 1; 2; 5; 10; 15; 30 minutes.
Recording Capacity:
- Dependant on sample rate and number of values recorded. Two values can be recorded
for up to 7 days at 10s intervals. More values or faster sample rates reduce the maximum
duration.
-RTC Battery Type:
- CR 1616 3V Lithium. Clock runs for >1 year without power.
RTC accuracy: Real Time Clock error <1second per day.

Neat little box.