7PG2113/4/5/6 Data Communications
©2010 Siemens Protection Devices Limited
Chapter 4 Page 33 of 38
5.4
Binary Output Status Points and Control Relay Output
Blocks
The following table lists both the Binary Output Status Points (Object 10) and the Control Relay Output Blocks
(Object 12).
While Binary Output Status Points are included here for completeness, they are not often polled by DNP 3.0
Masters. It is recommended that Binary Output Status points represent the most recent DNP “commanded” value
for the corresponding Control Relay Output Block point. Because many, if not most, Control Relay Output Block
points are controlled through pulse mechanisms, the value of the output status may in fact be meaningless.
Binary Output Status points are not recommended to be included in class 0 polls.
As an alternative, it is recommended that “actual” status values of Control Relay Output Block points be looped
around and mapped as Binary Inputs. (The “actual” status value, as opposed to the “commanded” status value, is
the value of the actuated control. For example, a DNP control command may be blocked through hardware or
software mechanisms; in this case, the actual status value would indicate the control failed because of the
blocking). Looping Control Relay Output Block actual status values as Binary Inputs has several advantages:
•
it allows actual statuses to be included in class 0 polls,
•
it allows change event reporting of the actual statuses, which is a more efficient and time-accurate
method of communicating control values,
•
and it allows reporting of time-based information associated with controls, including any delays before
controls are actuated, and any durations if the controls are pulsed.
The default select/control buffer size is large enough to hold 10 of the largest select requests possible.
Binary Output Status Points
Static Object Number:
10
Change Event Object Number:
11
Default Variation reported when variation 0 requested:
2 (Binary Output with flags)
Default Change Event variation 0 requested:
2 (Binary Output absolute time)
Control Relay Output Blocks
Object Number:
12
Point
Index
Name/Description
Default
Chang
e Event
Assign
ed
Class
Supported Control Relay
Output Block Fields
1
Binary Output 1
1
Pulse On/Latch Off
2
Binary Output 2
1
Pulse On/Latch Off
3
Binary Output 3
1
Pulse On/Latch Off
4
Binary Output 4
1
Pulse On/Latch Off
5
Binary Output 5
1
Pulse On/Latch Off
6
Binary Output 6
1
Pulse On/Latch Off
7
Binary Output 7
1
Pulse On/Latch Off
8
Binary Output 8
1
Pulse On/Latch Off
33
LED Reset
1
Pulse On/Latch Off
34
Settings Group 1
1
Pulse On/Latch Off
35
Settings Group 2
1
Pulse On/Latch Off
36
Settings Group 3
1
Pulse On/Latch Off
37
Settings Group 4
1
Pulse On/Latch Off
42 Auto-reclose
on/off
1 Pulse On/Pulse Off/Latch
On/Latch Off