Mitsubishi Electric Q03UDVCPU User Manual page 186

(4) When executing multiple SP.READ/SP.WRITE instructions simultaneously
When executing multiple SP.READ/SP.WRITE instructions simultaneously, ensure that SP.READ/SP.WRITE
instruction channels are not duplicated. If multiple SP.READ or SP.WRITE instructions are set to the same
channel, then cannot be executed simultaneously. If the same channel is shared by multiple SP.READ or
SP.WRITE instructions, those SP.READ/SP.WRITE instructions must be executed sequentially (one after
another), rather than simultaneously. The completion status of SP.READ/SP.WRITE instructions can be checked
using the completion device for SP.READ/SP.WRITE instructions.
(a) Channels
A channel is an area in the CPU module that contains the data handled by the SP.READ/SP.WRITE
instructions. Using multiple channels allows the CPU module on the host station to access the CPU modules of
multiple other stations simultaneously or read/write data at the same time from/to the same CPU module on
another station.
(b) Maximum available number of channels
The system provides eight channels that can be used along with the SP.READ/SP.WRITE instructions. Using
these eight channels allows the host station to execute eight SP.READ/SP.WRITE instructions simultaneously.
(c) An example of using channels
• When the CPU module on the host station accesses the CPU modules on multiple other stations
simultaneously:
Ensure that the host station uses a different channel for each request destination.
Channel 1:
Channel 2:
184
For writing to the CPU module 1
on another station
For writing to the CPU module 2
on another station
CPU module
on the host station
SP.WRITE
Channel 1
Channel 2
SP.WRITE
CPU module 1
on another station
CPU module 2
on another station