ABB REC 561 User Manual page 290

ABB Network Partner AB
Version 1.0-00
Apparatus control
The basic part of the reservation function is the reservation of the own
bay. When the reservation is made, no acceptance of selections from other
apparatuses can occur until all selection requests and reservations are can-
celled.
Reservation of the other bays can also be made. A request for reservation
is sent to these other bays. All bays should respond with an acknowledge-
ment that they have reserved the own bay for operations. After reception
of these signals, the reservation is considered successful and selection can
proceed.
To prevent that a reservation is not reset when the reserve request
becomes invalid, the reservation in the own bay and the acknowledgement
to the other bays are cancelled when the cancel reservation timer has
expired. The engineer should set this time to the operating time of the
slowest not hand driven disconnector.
One timer supervises the reservation. If the time until a successful reser-
vation is too long, the command sequence is stopped and an error message
is generated.
It is possible to ignore failing reservation of other bays, if the operator
wants to operate the apparatus. There is an override signal for this pur-
pose.
Blocking of the reservation function is possible. With an override, the
blocking of reservation on requests from inside the bay can be bypassed.
The reservation method is briefly explained in Fig. 2 and follows these
steps:
1. Select close/open from the station MMI
2. Reservation signal from the bay, which is to be operated
3. Transfer of acknowledgement and actual position indications from the
other bays
4. Performed selection is presented on the station MMI
5. Execution of the command from the station MMI
6. Release (cancel) of the reservation
1MRK 580 150-XEN
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