Command Sequence; Description - Siemens SIPROTEC 7SC80 Series Manual

Functions
2.15 Command Processing
• Acknowledgment and resetting commands for setting and resetting internal buffers or data states.
• Information status command to set/reset the additional information "information status" of a process object,
such as:
– Input blocking
– Output blocking
2.15.3

Command Sequence

Safety mechanisms in the command sequence ensure that a command can only be released after a thorough
check of preset criteria has been successfully concluded. Standard Interlocking checks are provided for each
individual control command. Additionally, user-defined interlocking conditions can be programmed separately
for each command. The actual execution of the command is also monitored afterwards. The overall command
task procedure is described in brief in the following list:

2.15.3.1 Description

Check Sequence
Please observe the following:
• Command input, e.g. via the Web Monitor
– Check Password → Access Rights
– Check Switching Mode (interlocking activated/deactivated) → Selection of Deactivated interlocking Rec-
ognition.
• User configurable interlocking checks
– Switching Authority
– Device Position Check (set vs. actual comparison)
– Interlocking, Zone Controlled (logic using CFC)
– System Interlocking (centrally, using SCADA system or substation controller)
– Double Operation (interlocking against parallel switching operation)
– Protection Blocking (blocking of switching operations by protective functions).
• Fixed Command Checks
– Internal Process Time (software watch dog which checks the time for processing the control action
between initiation of the control and final close of the relay contact)
– Setting Modification in Process (if setting modification is in process, commands are denied or delayed)
– Operating equipment enabled as output (if an operating equipment component was configured, but not
configured to a binary input, the command is denied)
– Output Block (if an output block has been programmed for the circuit breaker, and is active at the moment
the command is processed, then the command is denied)
– Board Hardware Error
– Command in Progress (only one command can be processed at a time for one operating equipment,
object-related Double Operation Block)
– 1-of-n-check (for schemes with multiple assignments, such as relays contact sharing a common terminal
a check is made if a command is already active for this set of output relays).
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SIPROTEC, 7SC80, Manual
E50417-G1140-C486-A1, Release date 12.2011