IDL 101
STRUCTURE OF THE BUS TOPOLOGY
HB_IDL101_E_V222.doc
29
Gantner Instruments Test & Measurement GmbH
RUN
ERR
A
In
-
A
O
ut
+
I/O
1
2
I/O
1
4
I/O
1
6
I/O
1
5
I/O
0
8
I/O
1
0
I/O
1
1
I/O
1
3
I/O
0
9
DIGITAL
A
GND
A
GND
Datalogger
without connected
Bus Termination
Datalogger
with connected
Bus Termination
Jumpers
R
A
A
U+
U+
B
B
U-
U-
R
R
R
R
R
d
d
t
t
u
u
Figure 4.6 Bus termination at the IDL 101
4.8. Shielding
In case of increased interference we recommend the use of shielded bus cables. Then, a shielding also should be done
for the cables from power supply and for the signal cables.
There are varying experiences and recommendations concerning the kind of shield connection. In general the shield
should be connected with the protective grounding (not DataGround!) at each bus connection. If necessary the shield
should be applied additionally several times along the course of the cable. With smaller distances, e.g. with stub cables,
the disturbance response 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 applying 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 protective grounding.
The
Datalogger IDL 101 does not have a direct shield connection on the device itself. Here the shield of the bus cable
can be connected to earth e.g. by so-called shield clamps.
