Hardware Manual COMBILOG 1020
98
There are varying experiences and recommendations concerning
the kind of shield connection. In general the shield should be con-
nected with the protector ground (not DataGround!) at each bus
connection. If necessary the shield should be earthed additionally
several times along the course of the cable. With smaller dis-
tances, e.g. with stub cables, the immunity from noise often is
improved if the shield is only applied to the stub cable exit.
Bus parties such as controls (PLCs), computers (PCs), repeaters
and interface converters, a.s.o., mostly offer the possibility of ap-
plying the shield directly to the appliance or to separate shield
rails. The shield rails offer the advantage of preventing possible
interfering signals from being led to the appliance via the shield.
These are already branched off before via the protector ground.
The C
OMBILOG housing
has no direct shield terminals. The
shield of the bus cable can be earthed e.g. by so-called shield
clamps.
TH. F
D I G I T A L
MEMORY CARD / PCMCIA
C
O
M
T
X
R
X
B
A
0
V
+
10
..
18
V
SUPPLY
RS 485
RS 232
I/
O
1
0
V
I/
O
2
0
V
I/
O
3
I/
O
4
I/
O
5
0
V
I/
O
6
0
V
RS-485 Busverbindung
zentraler
Erdungspunkt
Schirmgeflecht
Isolierung
0
V
0
V
Figure 10.7 Earthing of the bus line shield on the COMBILOG 1020
central
earthing point
braided shield
isolation
RS 485 bus connection
shield clamp
Summary of Contents for COMBILOG 1020
Page 1: ...COMBILOG 1020 Datalogger Hardware Manual Version 3 09...
Page 2: ...Hardware Manual COMBILOG 1020 2 Issue 03 11 2005 Technical data are subject to change...
Page 4: ...Hardware Manual COMBILOG 1020 4...
Page 6: ...Hardware Manual COMBILOG 1020 6...
Page 12: ...Hardware Manual COMBILOG 1020 12...
Page 86: ...Hardware Manual COMBILOG 1020 86 Bild 8 1 Example Master Slave System...
Page 169: ...Hardware Manual COMBILOG 1020 169...
Page 170: ...Hardware Manual COMBILOG 1020 170...
