Specifications

7SR242 Duobias Data Communications
©2010 Siemens Protection Devices Limited Chapter 4 Page 37 of 43
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 (CROB) 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:
x it allows actual statuses to be included in class 0 polls,
x it allows change event reporting of the actual statuses, which is a more efficient and time-accurate
method of communicating control values,
x 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
Object Number: 10
Default Variation reported when variation 0 requested: 2 (Binary Output Status)
Control Relay Output Blocks
Object Number: 12
Point
Index
Name/
Description
Default
Class
Default
Variation
Default
Event
Variation
Supported
CROB
Fields
Default
CROB
Fields
1 Binary Output 1 1 2 2 Pulse On
Latch On
Pulse On
2 Binary Output 2 1 2 2 Pulse On
Latch On
Pulse On
3 Binary Output 3 1 2 2 Pulse On
Latch On
Pulse On
4 Binary Output 4 1 2 2 Pulse On
Latch On
Pulse On
5 Binary Output 5 1 2 2 Pulse On
Latch On
Pulse On
6 Binary Output 6 1 2 2 Pulse On
Latch On
Pulse On
7 Binary Output 7 1 2 2 Pulse On
Latch On
Pulse On
8 Binary Output 8 1 2 2 Pulse On
Latch On
Pulse On
9 Binary Output 9 1 2 2 Pulse On
Latch On
Pulse On
10 Binary Output 10 1 2 2 Pulse On
Latch On
Pulse On
11 Binary Output 11 1 2 2 Pulse On
Latch On
Pulse On
12 Binary Output 12 1 2 2 Pulse On
Latch On
Pulse On
13 Binary Output 13 1 2 2 Pulse On
Latch On
Pulse On
14 Binary Output 14 1 2 2 Pulse On
Latch On
Pulse On
33 LED reset 1 2 2 Pulse On
Latch On
Pulse On
34 Settings Group 1 1 2 2 Pulse On
Latch On
Latch On
35 Settings Group 2 1 2 2 Pulse On
Latch On
Latch On