2
Method of operation
gas-net
C1 and C2
Page 2-8
1) Public switched telephone network or GSM wireless network (hardware
requirements: modem, COM2 interface)
2) Serial direct connection (hardware requirements: null-modem cable, COM2
interface)
3) TCP (hardware requirements: computer network, TCP/IP interface)
Independent of the data transmission type, the data connection established by
the integrated RDT offers multiple diagnostic and information gathering possi-
bilities.
For example, it is possible to poll archive data from a remote location. However,
the RDT may also be parameterized in such a way that a special event (e.g. a
correction alarm) will trigger a call at the center. This works as follows: Accord-
ing to the DSfG Specification, the entities generate
Attention telegrams
that are
forwarded to all other stations in form of a multi-address message in case of
special events. It is possible to separately define for each station that the center
will be informed spontaneously in case of particular generated telegram types
.
5
Each DSfG telegram contains a character for the telegram type (TTY). The telegram type
identifiers of the currently valid attention telegram types are the following:
Telegram type
TTY
Bus alarm
B
Freeze request
F
Hint H
End of billing period
I
Alarm L
New measurement
M
Parameter change
P
Warning W
Make-specific meaning
Y
Timesynch telegram
Z