Instruction Manual

Analog Input

Figure 4-1 shows the analog input circuitry of NI 6236 devices.

Figure 4-1. NI 6236 Analog Input Circuitry

Analog Input Circuitry

I/O Connector

You can connect analog input signals to the M Series device through the I/O

connector. The proper way to connect analog input signals depends on the

analog input ground-reference settings, described in the Analog Input

Ground-Reference Settings section. Also refer to Appendix A, NI 6236

Device Information, for device I/O connector pinouts.

MUX

Each M Series device has one analog-to-digital converter (ADC). The

multiplexers (MUX) route one AI channel at a time to the ADC through the

NI-PGIA.

Instrumentation Amplifier (NI-PGIA)

The NI programmable gain instrumentation amplifier (PGIA) is a

measurement and instrument class amplifier that minimizes settling times

for all input ranges. The NI-PGIA can amplify or attenuate an AI signal to

ensure that you use the maximum resolution of the ADC.

I/O Connector

AI <0..3>+

AI GND

NI-PGIA

Input Range

Selection

ADC

AI Data

Isolation

Barrier

Digital

Isolators

AI FIFO

AI <0..3>–

Mux