This communication is used to read and write data between center devices and PCL devices/CPU emulation devices.
When any data is written in the transmission FIFO of a center device and a transmission command is issued, the data is automatically transmitted in the form of interrupting each local area of cyclic communication.
The data returned from the local side is automatically stored in the reception FIFO of the center device.
In Motionnet, a PCL device is used to write commands and to read registers.
A CPU emulation device is used to read and write data of the connected LSI.