Mitsubishi MELSEC LJ71C24, User Manual

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App. - 71 App. - 71
APPENDIXES
(2) Program example
The following shows the program example of receiving data using the
nonprocedural protocol.
[I/O signals of the C24]
Device Purpose Device Purpose
X1003
CH1 Reception data read
request
Y1001
CH1 Reception data read
completion
X1004
CH1 Reception error
detection
— —
[Link special relay (SB), link special register (SW)]
Device Purpose Device Purpose
SB0049
Data link status of host
station
SW00B0.0
Data link status of each
station (Station number 1)
The data received in the C24 is transferred to the master station CPU module
and stored in the following devices.
(In the program example above, the receive data count is stored in D0, and the
receive data corresponding to the receive data count are transferred from W1001
to D1.)
Device Description
W1000 Receive data count
W1001 to W11FF Receive data
In the example above, data are not read out when a reception error is detected.
For the bidirectional protocol, programs for the reception error detection are not
required.