Mitsubishi Electric MELSEC iQ-R Series User Manual page 51

Link special relay (SB) areas and link special register (SW) areas
Link special relay (SB) areas and link special register (SW) areas related to the standby master function are listed below.
■Link special relay (SB) areas
Link special relay (SB) areas related to the standby master function are listed below.
• 'Refresh instruction at standby master switching' (SB0001)
• 'Forced master switching' (SB000C)
• 'Refresh instruction acceptance status at standby master switching' (SB0042)
• 'Refresh instruction completion status at standby master switching' (SB0043)
• 'Forced master switching enable status' (SB0046)
• 'Master switching request acceptance' (SB005A)
• 'Master switching request completion' (SB005B)
• 'Forced master switching request acceptance' (SB005C)
• 'Forced master switching request completion' (SB005D)
• 'Standby master station setting status of own station' (SB0062)
• 'Master station information' (SB0070)
• 'Standby master station information' (SB0071)
• 'Master station return specification information' (SB0079)
• 'Master/standby master operation status of own station' (SB007B)
■Link special register (SW) areas
Link special register (SW) areas related to the standby master function are listed below.
• 'Refresh instruction at standby master switching result' (SW0043)
• 'Forced master switching instruction result' (SW005D)
• 'Standby master station number' (SW0073)
■ON/OFF timing of link special relay (SB) areas
The following figure shows the ON/OFF timing of link special relay (SB) areas related to the standby master function.
'Master station information'
(SB0070)
'Master/standby master operation status of
own station'
(SB007B)
'Master switching request acceptance'
(SB005A)
'Master switching request completion'
(SB005B)
'Refresh instruction at standby master switching'
(program operation)
(SB0001)
'Refresh instruction acceptance status at standby
master switching'
(SB0042)
'Refresh instruction completion status at standby
master switching'
(SB0043)
*1 When turning on 'Master switching request acceptance' (SB005A), save data stored in RX, RY, RWr, and RWw to the devices and set
data stored in RX to RY, data stored in RY to RX, data stored in RWr to RWw, and data stored in RWw to RWr using a program. In
addition, turn on 'Refresh instruction at standby master switching' (SB0001).
After saving data stored in RX, RY, RWr, and RWw to the devices, wait a fixed number of scans and execute the processing that sets
data stored in RX to RY, data stored in RY to RX, data stored in RWr to RWw, and data stored in RWw to RWr using a program and the
processing that turns on the 'Refresh instruction at standby master switching' (SB0001).
For details, refer to  Page 47 Precautions.
ON
OFF
ON
OFF
ON
OFF
*1
OFF
OFF
OFF
OFF
ON
ON
ON
ON
1.3 Standby Master Function
1
1 FUNCTIONS
49