Input Sensors with PLC: 4-20 mA Current Loop

Industrial sensors are essential to many industrial control systems, to help controllers run tasks like check product performance, functionality, and safety. In this short course, learn about the common circuit used to connect analog industrial sensors to PLCs (programmable logic controllers), by exploring the 4-20 mA current loop circuit. Get introduced to the components of the 4-20 mA current loop circuit, including sensors, transmitters, power supplies, and receivers. Explore the role of transmitters in converting sensor values into a 4-20 mA electrical signal. Hear an overview about calculating mA current readings, wiring a temperature sensor to the PLC, and deciding when to use a load resistor in the loop. Plus, get answers to common questions about things like the importance of starting from 4 mA instead of 0 mA, or the reason for using 4mA as the lower range value in the current loop.