© National Instruments Corporation 4-1 SCXI-1125 User Manual
4
Theory of Operation

The section includes a brief overview and a detailed discussion of the

circuit features of the module. The two major modes of operation,

multiplexed and parallel mode, are discussed. Refer to Figure 4-1 while

reading this section.

Figure 4-1. SCXI-1125 Block Diagram

Gain

The SCXI-1125 has 12 different gain settings, from 1 to 2000, enabling

signal ranges ±5 V to ±2.5 mV. When the SCXI-1125 is used with a

terminal block that provides attenuation, the input range expands up to

1000 V. Refer to Appendix A, Specifications for a full list of input ranges.

Gain Select
Rear Signal Connector
AI 0+
AI 0–
AI 7+
AI 0
AI 7
AI 7–
AI 0
AI 7
+
Gain Select
+
+
–
+
–
MTEMP
Lowpass
Filter
Lowpass
Filter
Lowpass
Filter
Lowpass
Filter
Front Signal Connector
Analog
Multiplexer
Multiplexer
Control
Buffer
Analog
Bus
Switch
To
Analog
Bus
Scan
Clock
Digital Interface
and Control
SCXIbus Connector