Omega Speaker Systems PCI-DAS1001, PCI-DAS1002 manual  

4.2.1 Common Ground / Single-Ended Inputs

Single-ended is the recommended configuration for common ground connections. However, if some of your inputs are common ground and some are not, we recommend you use the differential mode. There is no performance penalty (other than loss of channels) for using a differential input to measure a common ground signal source. However the reverse is not true. The diagram below shows a recommended connection diagram for a common ground / single-ended input system

	l		ith
na					nd
Sig	ource		w
				on	G
	S		m
		om
		C			 

O ptional wire since signal source and A/D board share com m on ground

CH IN

LL G N D

I/O

C onnector

+

In p ut	To A /D
A m p

-

A /D Board

Signal source and A/D board sharing com m on ground connected to single-ended input.

4.2.2 Common Ground / Differential Inputs

The use of differential inputs to monitor a signal source with a common ground is a acceptable configuration though it requires more wiring and offers fewer channels than selecting a single-ended configuration. The diagram below shows the recommended connections in this configuration.

nal			ith
Sig		e	w			nd
	ourc				on	G
	S	om		m
		C					
							CH High
							CH Low
		Optional wire					LL GND
		since signal source
		and A/D board share
		com mon ground					I/O
							C onn ector
							Required connection
							of LL G ND to CH Low

+

Inp ut	To A /D
A m p

-

A /D Board

S ignal source and A/D board sharing com m on ground connected to differential input.

4.2.3 Common Mode Voltage < +/-10V / Single-Ended Inputs

This is not a recommended configuration. In fact, the phrase common mode has no meaning in a single-ended system and this case would be better described as a system with offset grounds. Anyway, you are welcome to try this configuration, no system damage should occur and depending on the overall accuracy you require, you may receive acceptable results.

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