Mitsubishi Electric MELSEC iQ-R Series User Manual page 85

Cyclic transmission assurance by watchdog counter
The watchdog counter is a function used to assure that normal cyclic transmission between stations on CC-Link IE TSN.
Using the watchdog counter, the master station and a slave station mutually monitor the data to be updated every
communication cycle; the master station monitors data received from a slave station and a slave station monitors data
received from the master station.
Whether the slave station is using the watchdog counter during a data link with the master station can be
checked with 'Watchdog counter operation status of each station' (SW01D0 to SW01D7).
Before using this function, check the firmware version of the RJ71GN11-T2. ( Page 320 Added and
Enhanced Functions)
■Operation
When the master station is powered off and on (when the CPU module is reset) or a slave station is disconnected and
returned, the master station stores insufficient time for the transient transmission time in 'Transient transmission additional
time (calculation value)' (SW007A).
If a value has been stored in 'Transient transmission additional time (calculation value)' (SW007A), add the value to the
setting values for "Communication Period Interval Setting" and "Transient transmission time' of "Communication Period
Setting" under "Basic Settings" for "System Parameter" of the master station.
■Setting method
The settings of the master station are not required to use the watchdog counter. However, the settings may be required
depending on a slave station used. ( Manual for the slave station used)
Precautions
• When the RJ71GN11-T2 is used as a local station, the watchdog counter cannot be used.
• When the RJ71GN11-T2 with the firmware version "10" or earlier is used or a slave station does not use the watchdog
counter, 0 is stored in 'Transient transmission additional time (calculation value)' (SW007A).
Network synchronous communication with a local station
A local station can link network synchronous communication and the inter-module synchronization function, so the local
station can operate in synchronization with the inter-module synchronization cycle of the master station. For details, refer to
the following.
 MELSEC iQ-R Inter-Module Synchronization Function Reference Manual
Program example
For program examples using the CC-Link IE TSN network synchronous communication function, refer to the following.
 MELSEC iQ-R Inter-Module Synchronization Function Reference Manual
• The operating status of each station can be checked with 'Information of CC-Link IE TSN network
synchronous communication function of each station' (SW01C0 to SW01C7) or 'Synchronous/
asynchronous operating status information of each station' (SW01C8 to SW01CF). To perform I/O control,
configure an interlock by using the corresponding bit of the special register (SW).
• When the CPU operating status of the relevant stations are currently STOP or PAUSE state, an inter-
module synchronous interrupt program is not executed. At this time, the operating status of the network
synchronous communication of each station ('Synchronous/asynchronous operating status information of
each station' (SW01C8 to SW01CF)) stores an asynchronous setting (0) in bits of the relevant stations and
bits of other stations are not changed.
1.6 CC-Link IE TSN Network Synchronous Communication Function
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1 FUNCTIONS
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