Series PC Manual V 1.0 - Rev. 3
– 03/01/01
DS Europe
21
The input impedance of data acquisition card, or multimeter, must be as high as possible
in order to avoid a drop of voltage on the cable and on transducer output filter resistance.
The input impedance must be in the proximity of 1 MOhm or greater; lower values in the
proximity of 100 KOhm should be avoided.
10.6. CONNECTION OF 4-20mA CURRENT OUTPUT
For the current outputs (options supplied upon request) the connection can be carried out
in the following two ways.
In
figure
9 we have a representation of connection for two current outputs.
The maximum load resistance R
Load
for the two current outputs is 600 Ohm.
10.6.1.
CURRENT CONNECTION: 4÷20 mA WITH VOLTAGE READING: 1÷5 V
Figure 9
shows the electrical connection of the current output (4÷20 mA), but read as a
voltage. This measurement is obtained by connecting a 250 ohm resistor to the output of
the transducer. The resistor, covered by the 4-20 mA, consents us to visualise a drop of
voltage of 1÷5 V.
The multimeter must be set to measure a DC voltage.
10.6.2.
CURRENT CONNECTION
Like the previous paragraph, still referring to figure 9, but, in order to read the current, do
not mount the 250 ohm resistor. Set the multimeter in order to read the 4÷20 mA current.
figure 9
: Electrical connection of two 4÷20 mA outputs with a voltage reading of 1÷5 Vcc.
