Internal structure of remote operation inverter control circuit and remote operation panel

When the operating console is far away from the frequency converter, the signal connection cable is very long, but the voltage of the frequency given signal circuit is very low and
the current is weak, making it extremely susceptible to external interference. For this purpose, a remote control panel (optional) can be used to suppress interference caused by long connections.
The circuit is shown in Figure (a), and the internal structure of the remote control panel is shown in Figure (b).
In the figure, FR is the forward running and stop command terminal of the frequency converter , and RST is the reset terminal , which is used to release the holding state after the frequency converter fault trips.