With the development of technology, the design of waterproof connectors is becoming smaller, and the purpose of miniaturization is to occupy less space. Of course, users should be allowed to install intensively, and intensive installation has heat dissipation problems, so the internal power consumption must be reduced. Therefore, the value of internal power consumption should also be paid attention to when selecting.
Nowadays, there are many isolated terminals with CPU as the core on the market, which have on-site editability and communication functions, and have high flexibility. For customers, it can reduce the inventory quantity and reduce the backlog of funds. The isolated terminal with CPU as the core will surely become the mainstream in this field.
Sanmenwan believes that there is another way to isolate the transmitter. The sensor and transmitter are integrated and must be placed in a designated location on site. At this time, the isolation terminal is generally placed in the cabinet of the central control room, and the isolation terminal in the cabinet distributes the power supply for the field transmitter. Which one to use depends on the PLC interface condition.
On-site debugging may cause a mismatch between the instrument and PLC interface. The sending device is a four-wire transmitter outputting 4-20mA, and the receiving end 4-20mA interface is a two-wire loop power supply mode. Direct connection will cause power conflicts. The solution is to use isolated terminals to receive and isolate 4-20mA on site, and install a dedicated circuit in the internal output part of the isolated terminals to match the two-wire loop power supply interface mode of the PLC.
