Redundant Addfems; Figure 3-9 Operating States From Power-On To Run - Siemens Add 7 AddFEM Manual

AddFEM
3.3.5

Redundant AddFEMs

Operating States at Module Redundancy
Generally both AddFEMs have equal rights so that each AddFEM can be either the
master or the reserve. In the following figure it is assumed that AddFEM(1) takes
over the master state.
System state
Start–up
1.
Solo mode
2.
Interfacing
3.
Redundant
4.
Figure 3-9 Operating states from POWER–ON to RUN
Table 3-3
Item
1.
2.
3.
4.
AddFEM
C79000–G8076–C900–03
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POWER–ON/Reset
AddFEM(1)
MASTER
START–UP
LINK–UP
ACTIVE
LINK–UP
ACTIVE
RUN ACTIVE
Explanations on the operating states
Description
After the supply voltage has been switched on or after a
hardware reset the AddFEM is in the START–UP state after
an initialization phase.
If the start–up is successfully, the master AddFEM(1)
changes to solo mode. AddFEM(2) has not yet exited to
START–UP state.
Checking and updating the reserve AddFEM(2) is carried
out again.
After the LINK–UP coupling the master and reserve
AddFEMs are in the RUN state.
Mode of Operation
POWER–ON/Reset
AddFEM(2)
RESERVE
START–UP
START–UP
LINK–UP
Update
PASSIVE
RUN PASSIVE
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