Which one would you prefer: 4-20 ma or 0-20 ma? Explain your answer.

Use of a 4-20 ma signal results in easy detection of a cable break by the PLC. This is because it only returns 0 ma. On using a 0-20 ma signal, the PLC loses its ability to detect any cable break. Since the return value is 0 ma which is the same as input, the PLC thinks that the signal is working perfectly. That is why 4-20 ma is preferred over 0-20 ma.