5
Functional description
Page 66
gas-lab
Q1
This is why the output of these message types is supported in different ways:
In contrast to single messages, centralized and group messages can be
output via digital outputs.
The events
Group message begins / Group message ends / Any message
of the group begins / Any message of the group ends
can be routed to the
DSfG bus with an attention telegram.
It can be determined for each group
upon which events such attention telegrams shall be generated and of
which type they shall be (
Alarm
,
Hint
or
Warning
).
The status of centralized, group and held group messages can be enquired
via DSfG.
Only the centralized message of the messages linked within a group is
entered in the message processing error listing and logbook to keep them
well structured.
A
Maintenance switch (M-switch)
is used to suppress group and/or centralized
messages if maintenance work has to be carried out.
The setting of this M-switch affects each group differently:
-
No influence
A set M-switch does not have any effect on the signalling reactions of
this group.
-
Suppression “towards telecontrol”
This means that, if the M-switch is set, the group does no longer
trigger any DSfG attention telegrams and the
Held group message
is
considered
not pending
.
-
Suppression of all signalling reactions without exception
In this case all messages generated by a group are suppressed if the
M-switch is set.
This means that the group neither generates held group nor group nor
centralized messages. Nevertheless, the centralized message is still
entered in the logbook and error listing.
If the M-switch is set, the main signaller no longer takes the group into
account.