Copyright © 2005
– 2021 R. STAHL TRANBERG AS. All rights reserved. Page 14 of 38
Section 4.02
VDR gateway
In order to send information to a VDR (Voyage Data Recorder) onboard the vessel, a
VDR gateway module may optionally be installed in the Master CPU unit. This device
passively listens to the network traffic and sends out information about the status of the
system and the various output modules .
The VDR gateway sends out two types of messages, 1) system status messages
according to a proprietary Tranberg protocol, and 2) alarm messages according to
NMEA-0183 ALR and ACK messages.
Electrical interface
Baud rate: 38.400 bps
Data bits: 8N1
Electrical: Isolated RS-422, output only
System status messages
The output string is a proprietary NMEA-0183 structure with the following setup:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
$PTRA
1
2
1
1
1
1
C
5
0
1
1
1
4
4
4
4
1
*
7
E
$
PTRA
Com
Sta
tu
s
Fa
ilCo
d
e
Net
1
Net
2
Net
3
Net
4
Nod
e
t
y
p
e
Nod
e
n
u
m
b
e
r
M
a
n
ua
l
o
’ri
d
e
Cha
n
n
e
l 8
Cha
n
n
e
l 7
Cha
n
n
e
l 6
Cha
n
n
e
l 5
Cha
n
n
e
l 4
Cha
n
n
e
l 3
Cha
n
n
e
l 2
Cha
n
n
e
l 1
*
Che
c
k
s
u
m
M
SB
Che
c
k
s
u
m
L
SB
Example:
$PTRA,1,2,1,1,1,1,C,5,0,1,1,1,4,4,4,4,1*7E
Packet length: 25 characters (normal), plus commas, carriage return and new line.
Total number of characters (including commas) sent are 4 2 characters, plus carriage
return and new line. Packet lengths are shorter in case of irregularities (see later in this
document).
Repetition rate: Packages are sent continuously at a rate of approx. 5 -10 packets per
second.
Explanations:
$PTRA: A fixed proprietary beginning of the telegram (Proprietary TRAnberg)
Comma: A comma sign (,), ASCII code 44 (0x2C)
Asterix: An asterix sign (*), ASCII code 42 (0x2A)
ComStatus: If minimum one node does not respond. 0 = Failure, 1 = Ok
FailCode: Common code for a fail on the module. 0 = Disregard, 1 = Ok, 2 = Net failure,
3 = Output failure, 4 = Net and output failure. If node is set to Manual override, the
code is 3 or 4.
Net1
– Net4: Status of the (up to) 4 independent power supply networks. 1 = On, 0=Off.
