Current loop is an electrical wiring configuration that transmits signals using two conductors and can be used for power delivery or analogue signalling. It is commonly used to measure factors like temperature, pH and other environmental factors, as well as to address grounding issues and other system components.
The devices connected to a current loop can be passive or active, and there are various types of current loops depending on their purpose. In electrical signalling, an analogue current loop is used to remotely monitor or operate a device over a pair of conductors, with only one active level at a time.
Current loops are widely used in process control applications, where they serve as the industry standard 4-20 mA current loop for transferring signals from process instrumentation to PID controllers, SCADA systems and programmable logic controllers (PLCs). They are also utilized to send controller outputs to modulating field equipment like control valves. These loops have a large user and equipment supplier base, and are preferred for their simplicity and immunity to noise. Some field devices can even be powered by the current loop itself, eliminating the need for batteries.
FAQ
What is a current loop used for?
A current loop is used for electrical signal transmission, power delivery or analogue signalling, and can be employed in various applications like process control systems and remote monitoring.
What are the types of current loops?
There are various types of current loops, including discrete control working loops, long telecom line loops and process controller loops.
What is the industry standard current loop used in process control systems?
The de facto industry standard current loop used in process control systems is the 4-20 mA current loop for transferring signals from process instrumentation to PID controllers, SCADA systems, and PLCs.
Conclusion
Current loop is an important electrical configuration that is widely used in process control systems for remote monitoring and electrical signal transmission. It offers simplicity, immunity to noise, and can eliminate the need for batteries in some devices. Understanding the applications and types of current loops is crucial for efficient process control and remote monitoring operations.
