Functions
2.27 Command Processing
SIPROTEC, 7SD5, Manual
C53000-G1176-C169-5, Release date 02.2011
492
2.27.3
Process Data
During the processing of commands, independently of the further allocation and processing of indications,
command and process feedbacks are sent to the indication processing. These indications contain information
on the cause. With the corresponding allocation (configuration) these indications are entered in the event log,
thus serving as a report.
A listing of possible operational indications and their meaning, as well as the command types needed for trip-
ping and closing the switchgear or for raising and lowering transformer taps and detailed information are de-
scribed in the SIPROTEC 4 System Description.
2.27.3.1 Method of Operation
Acknowledgement of Commands to the Device Front
All indications with the source of command LOCAL are transformed into a corresponding response and shown
in the display of the device.
Acknowledgement of commands to local/remote/DIGSI
The acknowledgement of indications which relate to commands with the origin “Command Issued = Local/ Re-
mote/DIGSI” are sent back to the initiating point independent of the routing (configuration on the serial digital
interface).
The acknowledgement of commands is therefore not executed by a response indication as it is done with the
local command but by ordinary command and feedback information recording.
Feedback monitoring
Command processing time monitors all commands with feedback. Parallel to the command, a monitoring time
period (command runtime monitoring) is started which checks whether the switchgear has achieved the desired
final state within this period. The monitoring time is stopped as soon as the feedback information arrives. If no
feedback information arrives, a response
„Time Limit Expired“
appears and the process is terminated.
Commands and their feedbacks are also recorded as operational indications. Normally the execution of a
command is terminated as soon as the feedback information (
FB+
) of the relevant switchgear arrives or, in case
of commands without process feedback information, the command output resets.
In the feedback, the plus sign means that a command has been positively completed. The command was as
expected, in other words positive. The "minus" is a negative confirmation and means that the command was
not executed as expected.
Command output/switching relays
The command types needed for tripping and closing of the switchgear or for raising and lowering transformer
taps have been defined during the configuration, see also SIPROTEC 4 System Description.
