Mitsubishi MELSEC LJ71C24, User Manual

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10 DATA COMMUNICATION USING THE NONPROCEDURAL PROTOCOL
• If LF is not received within the time set in the non reception monitoring
time (timer 0) after CR is received, the C24 stores the received data up to
CR to the buffer memory receive data storage area and turns on the
following signals to the CPU module.
When nonprocedural and non reception monitoring time format is 0:
Reception abnormal detection (X4/XB)
When nonprocedural and non reception monitoring time format is 1:
Reception data read request (X3/XA) 1
Reception abnormal detection (X4/XB)
Timer 0
set time
C
R
C24 side
External device
( 2)
[Format is 0]
Reception data read request (X3/XA)
[Format is 1]
1 In nonprocedural protocol, a message is received by the increase in
non reception monitoring time (timer 0) if the received complete code
and the received data count are not decided.
For the nonprocedural protocol at the non reception monitoring time
format, refer to the User's Manual (Application).
2 CR is handled as 1-byte data in the message.
2) When the receive complete code is changed and an arbitrary code is
designated (00
H
designated)
(User defined receive complete code data is added to the end of the
message and sent from the external device).
When the C24 receives the receive complete code data changed by the
user, it stores the receive data up to the receive complete code to the
buffer memory receive area and turned on the reception data read
request (X3/XA) to the CPU module.
External device
Reception data request (X3/XA)
Receive complete code data
C24 side
3) When the receive complete code is not designated (FFFF
H
designated)
Reading by the received data count is enabled.
Refer to (2) for a description of reading by the received data count.