The first place to look for stuff like this is the vendor's web page--in this case www.watlow.com. How did I know this? I guessed. You can typically guess 90% of company websites...
In a couple minutes I was able to find your controller and a document on how to communicate with it. If you email me I can send it to you (it's too big to post...).
Next, reading the document (which by the way contains a good basic primer on serial communications)I saw that one of the protocols you can use for communicating with the 942 is Modbus RTU. I can also send you a set of modbus drivers.
Hope this helps in thermal testing your chips...
Mike...
