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3 PROGRAMMING
3.2 Communication Example Using the Submaster Function
■When the operation is switched between the master operation and submaster operation
When the operation is switched between the master operation and submaster operation, a temporary data link error is
detected. ('Data link error status of own station' (SB0049) and 'Data link error status of each station' (SB00B0) turn on.)
While the operation is being switched, do not use cyclic data and the following signals.
The time until the operation is switched varies depending on how the operation is switched as described
below:
• When the operation is switched because the master operating station is down: up to three seconds
• When the operation is forced to be switched using 'Forced master switch command' (SB0019): up to three
seconds
• When the master station where "Return as Master Operation Station" has been selected for "Operation of
Master Station after Reconnection" in "Basic Settings" returns: up to 20 seconds
Programming for transient transmission
■Use of the REMFR, REMTO, REMFRD, REMTOD, SINFTYRD, and SINFSTRD instructions
The REMFR, REMTO, REMFRD, REMTOD, SINFTYRD, and SINFSTRD instructions can be executed only from the master
operating station. Create a program where these instructions can be executed only in the master operating station using
'Master/submaster function operation status of own station' (SB004E). (Set SB004E to off.)
Check that the data link status of the own station is normal. ('Data link error status of own station' (SB0049) is off.)
■Use of the WRITE, SWRITE, RIWT, and REQ instructions
Data can be written from both of a master operating station and submaster operating station; therefore, create a program
where data are not written in the same area at the same time. Especially, pay attention when the program of a master station
is used for a submaster station. Use 'Master/submaster function operation status of own station' (SB004E) to check whether
the own station is the master operating station or submaster operating station and do not execute the WRITE, SWRITE,
RIWT, and REQ instructions at the same time.
Check that the data link status of the own station is normal. ('Data link error status of own station' (SB0049) is off.)
■Dedicated instructions when the control is switched between the master operating station
and the submaster operating station or when the master station returns
Dedicated instructions may end abnormally. Create a program where transient transmission is performed again even if
dedicated instructions end abnormally.
Label name Description Device
bSts_DataLinkError Data link error status of own station SB0049
bOpe_DataLinkbySubmaster Master station information SB0070
bVal_Submaster_System Submaster station information SB0071
bSts_BatonPassError_System Baton pass error status of each station SB00A0
bSts_BatonPassError_Master Baton pass error status of master station SB00A1
bSts_BatonPassError_Station0 Baton pass error status of station No.0 SB00AF
bSts_DataLinkError_System Data link error status of each station SB00B0
bSts_DataLinkError_Master Data link error status of master station SB00B1
bSts_DataLinkError_Station0 Data link error status of station No.0 SB00BF
uVal_MaxSlaveNumber_BatonPass Maximum baton pass station number SW005A
uVal_MaxSlaveNumber_DataLink Maximum data link station number SW005B
uSts_Connection Connection status of own station SW0064
uVal_StationNumber_Master Master operating station number SW006D
uVal_StationNumber_Submaster Submaster operating station number SW006E
bnSts_BatonPassError_Station Baton pass status of each station SW00A0 to SW00A7
bnSts_DataLinkError_Station Data link status of each station SW00B0 to SW00B7
In_DataLink Own station data link status X1
In_NotDataLink_Other Other stations data link status X3
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