20 SERIAL COMMUNICATION INSTRUCTIONS
20.2 Executing the Protocols Registered for the Predefined Protocol Support Function
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• The protocol setting data written to the flash ROM is executed using the module specified by (U). All the protocols to be
executed follow the contents of the control data that has been stored in the device specified by (s) and later. The channel
specified by (n1) is used.
• One attempt of the instruction consecutively executes the specified number of protocols (by (n2); maximum 8).
• The completion status of the G(P).CPRTCL instruction can be checked with the completion device (d) and the completion
status indication device (d)+1.
• The following figure shows how the G(P).CPRTCL instruction operates when completing its execution.
The program execution status can be checked with the buffer memory (address: 4041H/4051H).
■Canceling protocol execution
A protocol can be canceled during its execution.
This function forcibly terminates the protocol being executed when a communication error occurs with the external device.
The function can be executed in the predefined protocol mode only.
• How to cancel the protocol execution
A cancellation can be requested using a sequence program.
Use the following buffer memory areas.
• Operation after the cancellation is requested
[Operation of the dedicated instruction (G(P).CPRTCL)]
The instruction completes with an error, and the error code is stored in (s)+0 (Execution result). If multiple protocols are being
executed sequentially, the cancellation-target protocol ('n'th protocol) is forcibly terminated, and the subsequent protocols are
not executed.
[Operation of the C24]
If the function is executed (a cancellation is requested) while no protocol is being executed, the C24 performs no processing.
If the function is executed in the mode other that the predefined protocol mode, the value in the corresponding buffer memory
area is ignored.
• Completion device (d)
This device turns on during END processing of the scan where the G(P).CPRTCL instruction completes, and turns off during the next END processing.
• Completion status indication device (d)+1
This device turns on or off depending on the completion status of the G(P).CPRTCL instruction.
When completed successfully: The device remains off.
When completed with an error: The device turns on during END processing of the scan where the G(P).CPRTCL instruction completes, and turns off during the
next END processing.
Address (decimal (hexadecimal)) Name Set value
CH1 CH2
16448 (4040H) 16464 (4050H) Protocol cancellation specification 0: No cancellation specified
1: Cancellation requested (by user)
2: Canceled (by the C24)
END0END0END0END0
OFF
OFF
OFF
OFF
ON
ON
Sequence scan
G(P).CPRTCL instruction
Completion device (d)
1 scan
Completion of the instruction
Completed successfully
Completed with an error
Execution of the instruction
Completion status
indication device (d)+1
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