ABB Relion 670 Series Technical Reference Manual page 689

1MRK505222-UUS C
Technical reference manual
QCRSV. If the bay is not reserved, the bay will be reserved and the acknowledgment
from output ACK_T_B is sent back to the requested bay. If the bay already is reserved
the reservation is kept and no acknowledgment is sent.
Blocking and overriding of reservation
If QCRSV function is blocked (input BLK_RES is set to true) the reservation is
blocked. That is, no reservation can be made from the own bay or any other bay. This
can be set, for example, via a binary input from an external device to prevent
operations from another operator place at the same time.
The reservation function can also be overridden in the own bay with the OVERRIDE
input signal, that is, reserving the own bay without waiting for the external acknowledge.
Bay with more than eight apparatuses
If only one instance of QCRSV is used for a bay that is, use of up to eight apparatuses,
the input EXCH_IN must be set to FALSE.
If there are more than eight apparatuses in the bay there has to be one additional
QCRSV. The two QCRSV functions have to communicate and this is done through the
input EXCH_IN and EXCH_OUT according to figure 347. If more then one QCRSV
are used, the execution order is very important. The execution order must be in the way
that the first QCRSV has a lower number than the next one.
Section 12
Control
683