Wire Break Monitoring

Thanks a lot For your answer . You are referring some PAC's in your thread for my explanation , May I know which make it is? . I am gonna Use Foxboro I/A series in my Plant , Do I have the same facility in my DCS? . And One More thing , Since You have mentioned about Burn-Out, I want to ask another question . Do You know about "Burn-Out Angle" of an instrument ? Is it an important parameter as for as Instrument Selection is concerned ?

Thanks In Advance.

Analog screen shots from Honeywell HC-900.
Discrete screen shot from Rockwell Allen Bradley Contrologix I/O card

I have never heard of burn-out angle. In what context is it used?

I have heard of burn-out direction, what direction the PV goes on sensor failure.

When controlling with a temperature sensor input, a configuration decision is made as to what direction the indicated process variable, PV, (temperature, in this case) will go when a failure of the sensor is detected by the controller.

For heating applications, the indicated PV is typically driven upscale, off scale, which will drive a reverse action control loop to 0% output, the result being a shutdown of energy into the process.

For cooling applications, the indicated PV is typically driven downscale, off scale, which will drive a direct action control loop to 100% output, providing unmodulated cooling.

Some controllers can drive the output to a fixed value.

Thanks a Lot for Your answer . Could you please elucidate your answer on that "open wire detection"? where does this contact sense resistor exactly located and how?