The frequency converter is divided into two categories: strong electric terminal and weak electric terminal.

The main results are as follows:

(1) strong electrical terminals refer to high-voltage and high-power terminals, which usually include RST power supply terminals, UVW motor terminals, P + and N-DC bus terminals, PB brake resistance terminals, E cooling aluminum sheet grounding terminals and so on. The energy of the frequency converter is transmitted through these terminals and then transferred to the motor after processing.

(2) weak current terminals include weak power supply terminals such as + 24V, com, + 10V, GND, FWD forward, REV reversal, X1~X7 multi-function definition terminals, RA, RB, RC internal relay output terminals, AO analog output terminals, VI, AI analog output terminals, RS485 communication terminals and so on.

How the frequency converter turns, how fast it turns, how it is now in the state, and how to work together with the peripheral equipment are all realized by the level of these terminals. Usually FWD, REV and X1~X7 send instructions to the frequency converter through the opening and closing of the contact signal of the external contactor. Generally, more normally open contacts are used to control, and some frequency converters can also define the positive and negative logic of the logic signal.