Mitsubishi MELSEC LJ71C24, Руководство пользователя

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12 DEDICATED INSTRUCTIONS
Cancellation of protocol execution
A protocol can be cancelled during its execution.
This function is used to end the protocol execution forcibly when a communication
error occurs with the other device.
This function is available for the predefined protocol mode only.
(1) Execution method for cancellation request
Execute a cancellation request from the sequence program.
The corresponding buffer memories are shown in the following table.
Address
Decimal (Hex)
CH1 CH2
Name Setting value
16448
(4040
H
)
16464
(4050
H
)
Protocol cancellation
specification
0: No cancellation specification
1: Cancellation request (Specified by User)
2: Cancel completed (set by C24N)
(2) Operation after execution of cancellation request
(a) Operation of dedicated instruction (CPRTCL instruction)
y The operation fails and the error code is stored in the execution result
((S)+0).
y When executing multiple protocols consecutively, if the cancellation is
requested to the nth protocol, the nth protocol is ended forcibly and the
protocols after the nth protocol are not executed.
(b) Operation of C24
y If the cancellation is requested when protocols are not executed, the
cancellation is completed in no-operation.
y If the cancellation is requested when the communication protocol setting is
other than the communication protocol mode, the value of the cancellation
designation area is ignored.
POINT
When the protocol with the communication type of "Send & receive" is cancelled,
execute the receive data clear after the cancellation.
When the response from the other device is slow, and data are received after the
cancellation, the receive data remains in the OS area (receive data area).
For details of the receive data clear, refer to Section 10.1.5.