PLC is a control system that can be used to monitor and control a variety of physical quantities, such as, temperature, working pressure, total flow, etc. This different physical quantity always continues to change, and the components used to test this physical quantity situation and transformation must truly reflect this different physical quantity transformation. After this main parameter is accurately measured, it is sent from the spot to the main control room, and it is necessary to ensure that the whole process of signal transmission is not wasted and affected. Therefore, the signal isolator can be used to transform or transmit the required high-quality signal.

The signal isolator is divided between source and active, and whether to use an active signal isolator or a microwave sensor signal isolator, which should be defined according to the transmitter applied on the spot.

Assuming that the transmitter is a four-wire system, then the transmitter's power supply system power supply and output signal are separated, the power supply is independently equipped, and then the output is immediately 4-50mA. Therefore, with the microwave sensor signal isolator, one in and one out can be. The electrical flow signal output terminal wire from the transmitter is connected to the signal isolator input end, and then the output terminal wire from the signal isolator is connected to the analog input channel of the PLC.

If it is a two-line transmitter, it is also a large number of applications today. Its power supply and current output signal use a set of lines, then its power supply system power supply must be presented by PLC, if the signal isolator is used, you need to use an active signal isolator.

The difference with the microwave sensor signal isolator is that the active signal isolator must be independently supplied with power. When wiring, if the two wires of the transmitter are connected to 4 and 6 of the figure, then from 8, 9 or 11, 12 wires to the PLC analog input input block.

It is the analog input block of the PLC300, with ABCD four options, such as the selection of D with two wire transmitters, and then the configuration software is also equipped to be applied.