Newbie’s question: What is the difference between a signal generator (process tester) and a Hart handheld communicator?

Both the signal generator (process tester) and the HART communicator can be used to test 4-20mA signals, but their specific functions differ. Signal generators are primarily used to simulate sensor output signals; they can provide an accurate current signal (such as 4-20mA) for testing or calibrating input modules or instruments in control systems, without the need to connect actual sensors. Basically, a signal generator allows you to inject a fixed-value signal into the circuit for testing without having to disconnect the wires. The HART handheld communicator can not only simulate 4-20mA signals for circuit testing, but also communicate with HART-enabled smart instruments via the HART (Highway Addressable Remote Transducer) communication protocol. It allows for reading instrument parameters or modifying their settings, such as changing the range or performing zero-point calibration. HART handheld devices generally do not require wire disconnection either; they can be connected through the field communication terminals. In simple terms, if you only need to perform loop testing without modifying the instrument parameters, the two are functionally similar. However, for more complex operations such as parameter reading or configuration changes, the HART communicator offers more functions. .

The handheld controller simulates a 4-20ma current in the circuit. There is a difference between active and passive signal generators; failing to disconnect the wires may result in additional signals being added on top of the original ones. Give it a try.

This post was last edited by qugd on 2023-12-22 at 11:18. A signal generator is an electrical signal source that can provide one or more specific electrical signals to the corresponding measuring instruments or sensors, such as current, voltage (including stable low voltages), pulses, waveforms, etc.; these signals represent physical quantities. The HART communicator, on the other hand, is a tool that can communicate with field devices or instruments using an analog current signal circuit; it operates in a digital communication mode. For these two different types of devices, when connecting to an electrical circuit, the method must be determined based on the specific characteristics of the device and the electrical circuit; it is not fixed. Some signal generators are compatible with HAR protocol communication, while certain HART field devices can also provide specific electrical signals for circuit testing.