After the inverter executes the h7a command, it will return to byte(8bit) state, where each bit represents a different meaning. As can be seen from the program, bit0 represents the running state of the inverter, that is, running or stopping, bit 1 represents forward rotation, bit2 represents reverse rotation, and bit7 represents whether it is abnormal.

This state is returned to plc by frequency converter through 485. When the plc receives the return data, it must be saved in the register. The address of this register is defined by yourself. It can be saved to M 100 ~ M 107 (the address used in this program) or m200~m207, as long as it is legal.

Then logic processing is performed based on the contents of the register.