User Manual RelAir R2M · 07/2018 · VERSION 1.1
12
RELAIR R2M
c) Decrypted Telegram
In the case that a registered meter sends an unencrypted telegram or the correct AES128 key is
stored, the data records contained in the wireless telegram are simply copied to the wired
M-Bus telegram. However, all uniquely identifiable idle fillers (2Fh) are removed:
RSP_UD:
Example
La
y
er
Byte No.
Name
Content
Bytes [hex]
1
Start
Start-Byte
68h
Data
Li
nk
La
y
er (
DLL)
2
L-Field
Telegram length
(from C-Field to checksum)
15h
3
L-Field
Telegram length
(from C-Field to checksum)
15h
4
Start
Start-Byte
68h
5
C-Field
SND_UD
08h
6
A-Field
Primary address (meter)
00h
7
CI-Field
72h (long Header)
72h
T
ran
s
po
rt L
ay
er (
T
P
L)
8
ID-Field
Identification number LSB
00h
9
ID-Field
Identification number
11h
10
ID-Field
Identification number (meter ID)
22h
11
ID-Field
Identification number MSB
33h
12
Manufacturer Manufacturer code LSB (Code = REL)
ACh
13
Manufacturer Manufacturer code MSB
48h
14
Version
Version
B8h
15
Type
Device type
07h
16
Acc.
Access number
01h
17
State
M-Bus State (e.g. error, alarm)
00h
18
Config.
Configuration field (e.g. encryption)
00h
19
Config.
Configuration field (e.g. encryption)
00h
20
DR1
DIF (BCD 8 digits)
0Ch
A
pp
lic
at
io
n
L
ay
er
(A
P
L)
21
DR1
VIF (volume [l])
13h
22
DR1
Value LSB
15h
23
DR1
Value
08h
24
DR1
Value (00000815 [l])
00h
25
DR1
Value MSB
00h
Checksum
h
DLL
Stop
Stop-Byte
16h
Telegram
– RSP_UD of a registered meter