Temperature control using micrologix 1500

Hi...
I used micrologix 1500 (1769-IT6 for temp reading) and using digital output to control modutrol motor to control temperature (modutrol motor movement forward to open gas valve and reverse to close the valve). Temp error that I want is +/- 3 deg c from setpoint. I want to use PID to control the modutrol motor. Any idea or comment on how to write the logic? This is for on/off mode controller.
Thanks.
Osias

See this thread

Thanks for reply.
I was try your ladder and it works fine. I have setup the PID paramter Kc=5.0, Ti=10. I want to maintain the pv close to setpoint. The temperature reading is 270 deg c and the setpoint is 280 deg c. Valve position is 50%. Valve timing is 31 second and number of step is 31 (I try 50 steps but step is to much). If I change setpoint to 260 deg c then pv is 250 deg c. Always different 10 deg c and valve position is 50%. This position will oscilate between 49% to 51%. How to setup the pid to have fast response if setpoint change? Any idea?
Thanks.
Osias.