U2B
5.2 Six wire connection
The grey and green wires that are provided in addition to the conventional
four wire connection pick off the actual value of the bridge excitation voltage
on the transducer and feeds it back to the appropriate measurement electron
ics. This then corrects the excitation voltage so that the set value is available
to the transducer loss free. Possible changes in the resistance of the cable
due to temperature or a cable extension are therefore constantly corrected,
even during a measurement. It is therefore possible to extend the cable
without any problem.
Fig. 5.1: U2B pin assignment
Earthing scheme (Green Line)
The cable shielding is connected in accordance with the Greenline scheme.
Under this scheme, the measuring system is enclosed in a Faraday cage.
Inside this cage, electromagnetic interference has no effect on the measuring
signal. The transformer section is protected from electromagnetic influences
by special electronic coding procedures.
When there is interference due to potential differences (balance current), the
connections between zero operating voltage and the body of the casing must
be separated on the amplifier and a potential equalisation line must be fitted
between the housing and the amplifier housing (highly flexible stranded wire,
2
10 mm
line cross section).
A0382 3.3 en/de/fr
wh (white)
Measuring signal (+) U
bk (black)
Bridge excitation voltage (−) U
rd (red)
Measuring signal (−) U
bu (blue)
Bridge excitation voltage (+) U
gn (green)
Sensor circuit (+)
gy (grey)
Sensor circuit (−)
ye (yellow)
Cable shielding, connected to housing
15
A
B
A
B
HBM