Mitsubishi MELSEC L Series User Manual page 147

(3) Precautions for performing data communication and notification
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a) When communicating data with the external device
1) When setting the no-communication interval time to infinite wait (set
value=0) in the initial setting of Q series C24, be sure to perform line
disconnection after the completion of data communication.
2) Only the no procedure protocol/bidirectional protocol data communication
can be performed in the programmable controller CPU with Q series C24
installed.
3) The Q series C24 automatically performs line disconnection processing if
no data exchange is performed during the no-communication interval
time.
The connection in progress signal (X12) and the modem initialization
completion signal (X10) turn off and the modem disconnection
completion signal (X14) turns on when the line disconnection processing
is performed.
b) When notifying to pager receivers
1) Turn on the notification-issued request signal (Y14) before the Q series
C24 modem/TA initialization is completed.
2) Notification processing is conducted when the notification-issued request
signal (Y14) turns from ON to OFF after the completion of modem/TA
initialization.
Therefore, notification processing is conducted when the programmable
controller CPU of the station with Q series C24 installed is in stop status,
or the programmable controller CPU stops due to error, since the
notification-issued request signal (Y14) is turned off in either case.
Write the data number for connection in the initial setting for GX
Configurator-SC.
3) When the notification-issued request signal (Y14) is turned OFF from ON
before initialization of the Q series C24 modem/TA, the processing will
end abnormally.
4) When the notification-issued request signal (Y14) is turned OFF from ON
during initialization of the Q series C24 modem/TA, notification
processing will be conducted after the completion of the modem/TA
initialization.
5) Notification processing is completed in the order of line connection,
message transmission, and line disconnection from Q series C24 for the
transmission station of the radio wave to the notification destination.
Therefore, even if the power to the notification destination equipment is
off, the notification processing will end normally as long as the above
processing is completed.
6) When the notification-issued request signal (Y14=ON) is turned ON
before notification processing is complete, some messages may not be
sent.
POINT
Turn on the notification-issued request signal (Y14) before the initialization
processing of the Q series C24 modem/TA is completed, and turn it off after the
initialization complete signal (X10) is turned ON (notification request).
3 COMMUNICATIONS BY THE MODEM FUNCTION
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