Omron SYSMAC C500-NC113 Operation Manual page 23

3. Commands
Commands such as START, ORIGIN SEARCH, and so on, are transferred
to the PCU by means of Intelligent I/O Write instructions. The PCU then in-
terprets and executes the commands.
4. Status Area
Status information such as the positioning action currently being executed is
written to the CPU Unit from the PCU by means of the CPU Unit's Intelligent
I/O Read instruction.
Note Instructions and data cannot be simultaneously transferred by the Intelligent I/O
Write instruction.
Section 1-5