ABB RELION REX640 Technical Manual page 1363

1MRS759142 C
REX640
Technical Manual
• Command authority: ensures that the command source is authorized to operate
the object
• Mutual exclusion: ensures that only one command source at a time can control the
object
• Interlocking: allows only safe commands
• Execution: supervises the command execution
• Command canceling: cancels the controlling of a selected object.
In direct operation, a single message is used to initiate the control action of a physical
device. The direct operation method uses less communication network capacity and
bandwidth than the SBO method, because the procedure needs fewer messages for
accurate operation.
The "status-only" mode means that control is not possible (non-controllable) via
communication or from LHMI. However, it is possible to control a disconnector
(DCXSWI) from AU_OPEN and AU_CLOSE inputs.
AU_OPEN and AU_CLOSE control the object directly regardless of
the set Control model. These inputs can be used when control is
wanted to be implemented purely based on ACT logic and no
additional exception handling is needed. However, in case of
simultaneous open and close control, the open control is always
prioritized.
REF 615
Selected
to operate
GUID-6372E77F-9AAA-46C4-B866-6A3B5E853EFD V1 EN
Figure 725: Control procedure in the SBO method
REF 615
1. Send reservationto other terminals
2. Receive response
REF 615
Section 9
Control functions
REF 615 REF 615
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