Process Station ABB FieldController 800
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7.2 Synchronization
The active FieldController (Primary) automatically ensures that the passive FieldController (Sec-
ondary) can take over in the event of redundancy. The adjustment of operating system, user pro-
grams and redundancy data necessary for this is performed via a redundancy connection, the re-
dundancy link. The connection is produced at the front of FieldController and is implemented via
an Ethernet cable, optionally 10BASE2 (BNC), AUI, or twisted pair cable (TP) .
When the FieldController is bootstrapped one of the two FieldControllers automatically becomes
the Primary. The second FieldController recognizes a Primary on the station bus and reports to
the Primary as Secondary.
A newly plugged-in FieldController recognizes automatically that another FieldController is
already active on the station bus and moves automatically into the passive status.
In the adjustment between the active FieldController and a passive FieldController, a connection
is established via the redundancy link. The user program is transmitted from the Primary to the
CPU.
The Secondary performs a cold start with these data and then logs on at the Primary. The current
process data are then transmitted to the Secondary. After successful transmission, both Field-
Controllers move to “sync“ status. From now on, the Secondary is ready for a bumpless redun-
dancy toggle. The relevant process data are adjusted cyclically.
The synchronization runs in parallel with the processing of the applications programs in the Field-
Controller.
Depending on the Boot priority of the Secondary, side-effects can be avoided when synchronizing
tasks. The higher the Boot priority of the Secondary compared to the processing priority of the
task (51 – 99), the faster the FieldController reaches Sync status.
See also Engineering Manual, System Configuration, Project Tree, Process Station.
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