CyberCertPrepOT Security FundamentalsOT Fundamentals: ICS/SCADA BasicsMEDIUMFree question
A flow transmitter loop reads 0 mA at the PLC analog input while the process is clearly running. Which fault best explains the reading?
- A.A broken wire or dead transmitter on the loop
- B.A flow of exactly zero on the pipe
- C.A scaling error in the engineering software
- D.A normal idle level for a 4-20 mA signal
Why A is correct
Live zero means a healthy loop never drops below 4 mA, so 0 mA signals an open circuit or lost power. A true zero flow would read 4 mA and scaling errors change the value without reaching 0 mA.
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