Mitsubishi MELSEC Q Series User Manual page 86

4 FUNCTIONS
Table 4.5 List of link special relays relating to the standby master function (1/2)
Number
SB0001 Refresh instruction at
(5E0 , b1) standby master switching
H
SB000C
Forced master switching
(5E0 , b12)
H
Refresh instruction
SB0042 acknowledgement status
(5E4 , b2) at standby master
H
switching
Refresh instruction
SB0043
complete status at standby
(5E4 , b3)
H
master switching
SB0046 Forced master switching
(5E4 , b6) executable status
H
SB005A Master switching request
(5E5 , b10) acknowledgement
H
SB005B Master switching request
(5E5 , b11) complete
H
SB005C Forced master switching
(5E4 , b12) request acknowledgement
H
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(4) Link special relays/registers (SB and SW) relating to the standby
master function
The following explains the link special relays and registers relating to the standby
master function. These are stored in the buffer memory.
When the standby master station is controlling the data link, its applicability is
basically identical to that of the master station. When the standby master station
is operating as a local station, its applicability is identical to that of the local
station.
(a) Link special relays (SB)
The link special relays (SB) relating to the standby master function are as
follows : The figures in parentheses in the number column indicate buffer
memory addresses and bit locations.
Example: When the buffer memory address is 5E0
(5E0
Name
Gives refresh instruction for cyclic data after the data link control
is transferred to the standby master station.
0: No instruction
1: Instructed
Forcefully transfers the data link control from the standby master
station that controls the data link to the master station that stands
by in case the standby master station becomes faulty.
0: No request
1: Requested
Indicates whether the refresh instruction at standby master
switching has been acknowledged or not.
0: Not acknowledged
1: Instruction acknowledged
Indicates whether the refresh instruction at standby master
switching is complete or not.
0: Not complete
1: Switching complete
Indicates whether the forced master switching (SB000C) signal
can be executed or not.
OFF: Cannot be executed.
ON: Can be executed.
Indicates the acknowledgement status of the standby master
station when it has received a master switching request from the
line.
OFF: Not acknowledged
ON: Request acknowledged
Indicates whether or not the switch from the standby master
station to the master station is complete.
OFF: Not complete
ON: Complete
Indicates whether a forced master switching request has been
acknowledged or not.
0: Not acknowledged
1: Instruction acknowledged
, b0)
H
Description
MELSEC-Q
and the bit location is 0:
H
Applicability
( : Applicable, : Not applicable)
Master
Local station Offline
station
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