Data Translation DT9871, User Manual

Page: 59 / 134

Wiring Signals
59
Connecting Current Loop Inputs to Voltage Channels
Voltage channels on the DT9873 and DT9874 instruments have an input range of ±10 V or
±60 V. You select the input range for each channel using software.
With the 24-bit A/D converter, high current, high side current shunts can be used for
resolutions of less than 0.01 A on a 100 A range.
Typical Shunts:
• Vishay WSMS5515
.2 m

- 2W - 100A - 20mV
• Vishay CSM2512S
10 m

- 1W - 10A - 100mV
• Deltec MUB-500-50
.1 m

- 25W - 500A - 50mV
Notes: On the DT9874 instrument, channels 32 to 47 correspond to the voltage input
channels.
Figure 23 shows an example of wiring signals to measure ±20 mA using the ±10 V input
range.
Figure 23: Connecting a Current Loop Input to a Voltage Channel to Measure ±20 mA
250

shunt resistor
28 V (can be up to ±60 V)
±20 mA
Load
+
–
Voltage Channel
– Sense +Sense
1 2 4 3
Shield
In this example, the input range is ±10 V.