Wavecom W74PC V8.7.0 - Manual (Page 275)

WAVECOM Decoder W74PC, W-PCI/e, W-CODE, W-CLOUD Manual V8.7.0 Transmission Modes
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In the newer VDEW system the rhombic labeling and the manufacturer identification are combined into
one field of three digits, called EVU number (EVU#:).
Call number ZVEI and VDEW (Ruf#:)
Three digits are used. The hundred-position digit is transmitted first, the one-position digit last. Group
calls are transmitted as pseudo-tetrads of '1111' (16). For a group call in the 10s range the digit repre-
senting 1s is filled with logical ‘1’. For a group call in the 100s range, the 1s and 10s digit are filled with
logical ‘1’, and for a 1000s range call all 12 bits are filled with logical ‘1’.
EVU and call number are transferred in a block of six digits. The partitioning is either 3 digits for either
items or 2 EVU digits plus 4 call number digits. The chosen variant cannot be derived from the data, so
both versions are displayed.
The following picture shows a trace of a VDEW transmission with basic telegram and a single follow-up
telegram, displaying both versions of partitioning, i.e., 3 + 3 as well as 2 + 4.
The next picture shows a transmission which can be either a ZVEI message or a VDEW message without
follow-up telegram.
The user has to decide from the context which transmission standard was used. In case of a VDEW trans-
mission without follow-up telegram, the rhombic labeling and the manufacturer identification have to be
interpreted as EVU#.