Mitsubishi MELSEC LJ71C24, User Manual

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10 DATA COMMUNICATION USING THE NONPROCEDURAL PROTOCOL
10.1.5 Receive data clear
For the data reception by a nonprocedural protocol, if the transmission of data from a
transmitting device is interrupted due to trouble occurring, it may be necessary for the
data received up to the present time are cleared in the receiving device and for the
data to be received again from the start.
The methods for clearing reception data in the C24 are shown below. Either method
may be used to clear received data as necessary.
1) Clear the reception data by the dedicated instruction "CSET." (Refer to (2)).
2) Write to/read from the receive data clear request (address: A8
H
/148
H
). (FROM/TO
instruction) (Refer to (3)).
3) Clear the reception data by GX Works2 (Refer to (4)).
REMARKS
When transmitting data to an external device from the C24, do not execute a clear
request of the receive data by FROM/TO instruction or GX Works2.
If a receive data clear request is executed when transmitting data to an external
device, The C24 stops data transmission and terminates the dedicated instruction
for transmission abnormally. (The transmission completed signal does not turn ON.)
If a receive data clear request is executed during data reception, the data received
up to that point are cleared.
(1) Receive data clear processing
The C24 performs the following processing when the receive data clear is
performed.
• The data received up to that point can be ignored.
• The receive data count up to the current point is "0".
(The receive area in the buffer memory is not initialized).
• Set to the status prior to the start of data reception.