The master station checks that the send request bStartDirection (M0) is turned on, and transfers contents of uTransferFrom [0] to [3] to the send data W0 to
W3.
When the transfer is completed, the master station turns on B0.
The local station checks that B1000 is turned on, and transfers contents of the receive data W1000 to W1003 to uTransferTo [0] to [3] (D0 to D3).
When the transfer is completed, the local station turns on B0.
The master station checks that B1000 is turned on, and turns off B0.
The local station checks that B1000 is turned off, and turns off B0.