9. Program
43
9.1.1. Communications Data Flow
The following figure shows the data flow from when the Controller (Serial Communications
Unit) issues command data via serial communications to the destination device until when it
receives the response data from the destination device.
1.
Executing the
communications sequence
The CPU Unit executes the protocol macro instruction
(Instruction: ExecPMCR) with the sequence number
specified in the program, and loads the
communications sequence (protocol macro data)
registered in the Serial Communications Unit.
↓
2.
Sending a command
The Serial Communications Unit issues the send
message (command data) to the destination device
based on the sequence number specified in step 1.
↓
3.
Response receive
processing
The Serial Communications Unit receives the message
(response data) from the destination device, and stores
it in the specified internal memory of the CPU Unit.
Содержание V400-R2 Series
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