Mitsubishi Electric Melsec QJ71LP21 Reference Manual page 354

7 APPLICATION FUNCTIONS
Status of target station
Stop link by specifying host
Stop link by specifying specified station
Stop link by specifying all the stations
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3) Execution using the sequence program (Not allowed for the Basic
model QCPU and safety CPU)
The data receiving between the CPU module and network modules
(link refreshing) is not stopped or restarted by stopping/restarting the
cyclic transmission.
Thus, it is necessary to stop/restart link refreshing by the sequence
program using the CPU module's special relay (SM).
Link refreshing is stopped or restarted by Host data link status
(SB0049) as shown in the following program.
Host data link status
Off: Being executed
On: Stopped
SB0049
4) Whether or not the restart operation is possible as determined by the
stop operation method
The priority order of startup and stop is as follows:
Link startup < Link stop < Forced link startup.
Type of restart
operation
Target
POINT
Link start cannot be done even if the link start operation is performed to an offline-
mode station (disconnected from the network).
No error will be detected, in this case, because no response is returned from the
target station.
Refresh between the network modules and the CPU
Off: Refreshes
On: Does not refresh
SM256
Link startup
Designated
station Host
station
: Startup possible
MELSEC-Q
Forced link startup
Specified
All stations Host
station
: Startup not possible
All stations
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