ABB REO 517 Applications Manual page 256

246
Interlocking
If the busbar is divided by bus-section circuit breakers, the signals from the bus-section
coupler bay (A1A2_BS), rather than the bus-section disconnector bay (A1A2_DC)
must be used. For B1B2_BS, corresponding signals from busbar B are used. The same
type of module (A1A2_BS) is used for different busbars, that is, for both bus-section
circuit breakers A1A2_BS and B1B2_BS.
6LJQDO
A1A2OPTR Signal if there is no bus-section coupler connection between bus sections
A1 and A2.
A1A2CLTR Signal if a bus-section coupler connection exists between bus sections A1
and A2.
VPA1A2TR The switch status of A1A2_DC is valid.
EXDUP_BS Signal if there is no transmission error from the bay that contains the above
information. This signal is taken from the data valid output on the command
function block.
For a line bay in section 1, these conditions are valid:
&KDSWHU
&RQWURO