Multiple Command Output; Behavior During Special Operating Conditions - Siemens SIPROTEC PROFINET IO Manual

2.9.3

Multiple Command Output

Command processing in the SIPROTEC device operates in a 100 ms cycle. This includes:
• Command checking
• Command output
• Feedback monitoring
• Generating positive or negative command feedback
After the issuing of a positive command feedback, which is also entered as a change of the value of the
switchgear position in the cyclic input telegram via PROFINET IO, command processing remains active for one
cycle max. (100 ms).
As the SIPROTEC device does not process several commands in parallel, an additional command, which is
received within an active command processing, is rejected with "1 out of n error" and is not executed.
If it is desired that the IO controller issues 2 or more commands directly one after another, a time delay of
100 ms must be observed after reception of the positive command feedback in the cyclic input data until issuing
of the next command. This ensures that the subsequent command is executed reliably.
2.9.4

Behavior During Special Operating Conditions

• The IO controller detects a change of the switchgear position not initiated by the IO controller (for example,
circuit-breaker trip) by the change of the value of the switchgear position in the associated bit positions of
the input telegram.
If, for example, the IO controller wants to restart the switchgear that was switched off locally, it must first
transmit the ACTUAL value (OFF) or idle state via PROFINET IO and can subsequently restart the
switchgear by setting the TARGET value (ON).
• The IO controller detects when a switching operation requested via PROFINET IO cannot be executed,
because the switching authority is set to LOCAL, for example, or the associated bay interlocking is not
satisfied. The IO controller recognizes this because the feedback of the double command/single
command in the PROFINET IO input telegram is not updated according to the TARGET switch position
(activate a feedback monitoring time in the IO controller if necessary).
Before a new switching attempt, the ACTUAL switch position for switchgear must first be transmitted again
according to the input telegram or idle state via PROFINET IO in the output telegram.
• The behavior during communication interruptions is described in Chapter 2.10.
SIPROTEC 4, Communication Module PROFINET IO, Communication Profile
C53000-L1840-C360-1, Edition 08.2012
2 PROFINET IO in SIPROTEC
2.9 Executing Switching Operations via PROFINET IO
51