Siemens 7SR224 Technical Manual page 183

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
All objects are default class 2
Point
Name/Description
Index
1 Binary Output 1
2 Binary Output 2
3 Binary Output 3
4 Binary Output 4
5 Binary Output 5
6 Binary Output 6
7 Binary Output 7
8 Binary Output 8
9 Binary Output 9
10 Binary Output 10
11 Binary Output 11
12 Binary Output 12
13 Binary Output 13
14 Binary Output 14
15 Binary Output 15
16 Binary Output 16
17 Binary Output 17
18 Binary Output 18
19 Binary Output 19
20 Binary Output 20
21 Binary Output 21
22 Binary Output 22
23 Binary Output 23
24 Binary Output 24
25 Binary Output 25
©2010 Siemens Protection Devices Limited
7SR224 Argus Data Comms
Supported Control Relay Output Block
Fields
Pulse On/Latch On
Pulse On/Latch On
Pulse On/Latch On
Pulse On/Latch On
Pulse On/Latch On
Pulse On/Latch On
Pulse On/Latch On
Pulse On/Latch On
Pulse On/Latch On
Pulse On/Latch On
Pulse On/Latch On
Pulse On/Latch On
Pulse On/Latch On
Pulse On/Latch On
Pulse On/Latch On
Pulse On/Latch On
Pulse On/Latch On
Pulse On/Latch On
Pulse On/Latch On
Pulse On/Latch On
Pulse On/Latch On
Pulse On/Latch On
Pulse On/Latch On
Pulse On/Latch On
Pulse On/Latch On
Chapter 4 Page 49 of 76