temperature control in GE plc's

I am new to a lot of this stuff so just bear with me. We use a lot of GE plc's around the facility and I will be setting one up soon on a machine retrofit. Basically we need to bring a thermmocouple input into the plc and then do all the neccessary scaling and pid instruction and then fire an output that will energize a relay to provide power to a band heater. My question is pretty basic as to how to set the logic up to do this such as how to scale where to move the data and how to setup the pid loop ( which I am assuming will just be the PID instruction for GE. If any one can walk me through the basic steps how to do this or has a basic logic circuit that shows this that would be great. Thanks

http://claymore.engineer.gvsu.edu/~jackh/books/plcs/pdf/plcbook4_2.pdf

http://www.jashaw.com/tutorial/index.html

What you just asked is not particularly basic the first book will explain both of them however do a search on this site under Ron Beaufort he has posted several articles on PID "what is I" "what is P" etc for linear scaling he also has another article on Y=mx+b (linear scale)

When you configure a thermocouple input module in a GE Fanuc PLC, you define whether you want the temperature data to be reported in Celsius or Fahrenheit. The units are generally tenths of a degree, so an actual temperature of 123.4 degrees will show up as a value of 1234 in the %AI register assigned to the channel.

How closely do you need to control the temperature? If you can tolerate some fluctuations, then you may be able to adequately control it by simply energizing the relay when the temperature falls below some level and turning it back off when the temperature gets too high.

Thats a handy feature should have mentioned above that I was not familiar with that model