Siemens SIPROTEC 6MD665, Manual

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2 Functions
20
6MD665 Manual
C53000-G1876-C103-3
Device-internal commands
These commands do not directly operate binary outputs. They serve for initiating inter-
nal functions, communicating the detection of status changes to the device or for
acknowledging them.
• Manual overriding commands to manually update information on process-depen-
dent objects such as indications and switching states, e.g. if the communication with
the process is interrupted. Manually overridden objects are flagged as such in the
information status and can be displayed accordingly.
• Tagging commands are issued to establish internal settings, e.g. deleting / preset-
ting the switching authority (remote vs. local), a parameter set changeover, data
transmission block to the SCADA interface, and measured value set-points.
• Acknowledgment and resetting commands for setting and resetting internal buffers
or data stocks.
• Information status command to set/reset the additional information "information
status" of a process object, such as:
– Acquisition blockage
– Output blocking.
Sequence in the command path
Security mechanisms in the command path ensure that a switch command can be
carried out only if the test of previously established criteria has been successfully com-
pleted. In addition to general fixed prescribed tests, for each resource separately
further interlocks can be configured. The actual execution of the command job also is
then monitored. The entire sequence of a command is described briefly in the follow-
ing.
Checking a command job
Please observe the following:
• Command entry, e.g. using the keypad on the local user interface of the device
– Check password
⇒
access rights
– Check switching mode (interlocking activated/deactivated)
⇒
selection of deac-
tivated interlocking status.
• User configurable Interlocking checks
– Switching authority
– Device position check (setpoint vs. actual comparison)
– Interlocking, zone controlled (logic using CFC)
– Interlocking, system interlocking (centrally, using SICAM)
– 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 con-
tact)
– Setting modification in process (if setting modification is in process, commands
are denied or delayed)