PCI-1202/1602/180x Series Card
Multi-Function Boards
User Manual/ Ver. 4.8/ Mar. 2015/ PMH-0014-48/ Page: 24
2.4
Analog Input Signal Connection
The PEX-1202 and PCI-1202/1602/1800/1802 series can measure single-ended or differential-type analog
input signal. Some analog signals can be measured in both modes. However, some analog signals only can be
measured in one or the other. The user must decide which mode is suitable for measurement.
In general, there are 4 different analog signal connection methods (shown from
Figure 2.4-1
to
Figure 2.4-5
).
The connection in
Figure 2.4-1
is suitable for grounded analog input signals. The
Figure 2.4-3
connection is
used to measure more channels than in
Figure 2.4-1
, but it is only suitable for analog signals that large than 1
V. The connection in
Figure 2.4-4
is suitable for thermocouple and the
Figure 2.4-5
connection is suitable for
floating analog input signals.
Note: In Figure 2.4-4 the maximum common mode voltage between the analog input source and the AGND
is 70 V
p-p
, so the user must take care that the input signal is under this specification first. If the common
mode voltage is over 70 V
p-p
, the input multiplexer will be permanently damaged!
The simple way to select your input signal connection configuration is listed below.
1.
Grounded source input signal
see Figure 2.4-1
2.
Thermocouple input signal
see Figure 2.4-4
3.
Floating source input signal
see Figure 2.4-5
4.
If Vin > 1 V, the gain<=10 and more channels are needed
see Figure 2.4-3
5.
Current source input signal
see
Figure 2.4-6
If you are unsure of the characteristics of your input signal, follow these test step:
1.
Step1 : Try and record the measurement result of the Figure 2.4-1
2.
Step2 : Try and record the measurement result of the Figure 2.4-5
3.
Step3 : Try and record the measurement result of the Figure 2.4-3
4.
Compare the three results and select the best one
