How to Control the WATLOW 922 series PID Controller using Labview?

[Vikram -Hardware Techy]

Hello All,
I m using Labview to control WATLOW 922 series
PID controller using Labview. Have been successful in
establishing a communication thru the RS232 port.
Now got to make temperature variations(increas/decrease) in steps.It should measure the temperature and graph it.


Can anybody please help me out in this case.
I am new to Labview.

regards,
Vikram Malik

[Brian_Vibert]

You will need to get a manual from Watlow that describes the commands and their syntax to control the temperature. If you have this information and cannot make it work then please give us more details on what doesn't work.

Brian

[Vikram -Hardware Techy]

Hi Brian,
Yes, I have the manual.
I would like to tell more about the whole thing.
This PID controller is for the Heat chamber.Trying to vary temperature for specified time by the user and take the readings.

Controller specifications:
Dual channel PID controller,
1/4 DIN sized ramping temperature control,
Accepts dual inputs, one per channel,
Includes Type R,J,T thermocouple, a 1 degree OR 0.1 degree RTD input.

I am trying to use the PID example.Need to know how do i use this with the Controller.
For example: = SP1 50 (string) means I am setting the temperature to 50 deg. Celsius.
Another question do I need to use a DAQ board for this.

Hope its clear what exactly I need.
Please give me ur fax. Number and Telephone No.
at this email : malivik@iit.edu

regards,
Vikram Malik

[Brian_Vibert]

You shouldn't need to use the PID example because all the PID stuff is done in the controller. Use the serial communication functions to write your string (SP1 50) to your controller and read the reply back. See the example vis for examples of how to perform serial communication. Once you get good communication I would make it into a sub-vi and use it for all your coomunication with the Watlow. Then write your code to set the temperature at intervals and take readings. You should be able to find some examples of user interface vis to help you figure out how to let the user set the intervals.

Whether or not you need a DAQ board depends on what data you are trying to collect, if you just need to monitor the temperature of the chamber a
nd the accuracy of the controller is sufficient then you don't need a DAQ board. If you are trying to collect some other data then yes, you will need some other equipment.

I hope this helps!
Brian