
Instrumentation for PLC Engineers
The half of the loop that is not code. Follow one measurement from the transmitter in the field, down the 4-20 mA loop, into the analog card, through NORM_X and SCALE_X into engineering units, out again to a valve, and back to the control room when the reading is wrong.
- Trace one loop from sensing element to final element and say which half a wrong reading is in
- Read a transmitter's range and span, and work out the process variable at any current
- Wire two-, three- and four-wire transmitters, and tell a fault current from a measurement


