Frequency converter step operation and inching operation circuit

In the figure, REV is the reverse run and stop command terminal . FWD is the forward running and stop
command terminal, and JOG is the jog terminal. CM is the common terminal for contact input, and X4 and x5 are acceleration/deceleration time selection terminals .
Through switches Sl, sz. Four types of acceleration/deceleration time can be selected.
    In some production processes, downtime is not allowed. Once the frequency converter trips due to a fault during variable frequency operation , it must
switch to power frequency operation. In addition, some occasions require switching between power frequency operation and variable frequency operation.