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analog ground. The inputs are protected against maximum input voltages 
of up to ±15 V powered off and ±30 V powered on.

Exceeding the differential or common-mode input voltage limits distorts input 

signals. Exceeding the maximum common-mode input voltage rating can damage the 
SCXI-1141/1142/1143 module, the SCXIbus, and the DAQ device. NI is not liable for any 
damage resulting from such signal connections.

All eight channels have fully differential inputs, so you can 
ground-reference the signals you measure. If the signals connected to the 
differential amplified inputs are not ground referenced, connect a 100 k

Ω 

resistor from the negative input to ground to provide a DC path for the input 
bias currents. If you do not do this, the bias currents of the instrumentation 
amplifiers of the nonreferenced channels charge up stray capacitances, 
resulting in uncontrollable drift and possible saturation.

The recommended SCXI-1304 or SCXI-1305 terminal block has all necessary 

circuitry for AC or DC coupling and for floating or ground-referenced signals. The 
SCXI-1304 AC/DC Coupling Terminal Block Installation Guide and SCXI-1305 AC/DC 
Coupling BNC Terminal Block Installation Guide have instructions for signal connection. 
Figures 2-2 through 2-5 provide supplemental information on connecting signals to the 
SCXI-1141/1142/1143 module.

Figure 2-1 illustrates how to connect a ground-referenced signal source to 
an SCXI-1141/1142/1143 module channel.

Figure 2-1.  Ground-Referenced Signal Connection

IN–

IN+

SCXI-1141/1142/1143