PLC glossary
4–20 mA
A sensor sends a changing electrical current to represent a measurement. Usually 4 milliamps means the range's bottom and 20 its top.
- Also called
- 4-20 mA, 4–20mA, current loop
- On site
- A tank instrument sends a small current through its cable to report the water level.
- Siemens
- Configure the analogue input's current range and scale its reading to engineering units.
- Rockwell
- Configure the analogue module's current range and scaling to match the transmitter.