Omega Speaker Systems PCI-DAS1002, PCI-DAS1001 manual  

4.2.4 Common Mode Voltage < +/-10V / Differential Inputs

Systems with varying ground potentials should always be monitored in the differential mode. Care is required to assure that the sum of the input signal and the ground differential (referred to as the common mode voltage) does not exceed the common mode range of the A/D board (+/-10V on the PCI-DAS1000). The diagram below show recommended connections in this configuration.

	rce		mon
l Sou
Signa	ith C
	w	om		ltage
	M	ode		Vo	 
				G N D

The voltage differential betw een these grounds, added to the m axim um input signal m ust stay w ithin +/-10V

CH High

CH Low

LL GND

I/O

C onn ector

+

Inp ut	To A /D
A m p

-

A /D Board

Signal source and A /D board with com m on m ode voltage connected to a differential input.

4.2.5 Common Mode Voltage > +/-10V

The PCI-DAS1000 will not directly monitor signals with common mode voltages greater than +/-10V. You will either need to alter the system ground configuration to reduce the overall common mode voltage, or add isolated signal conditioning between the source and your board.

Is o la tio n

B a rrie r

arge com		mon
					￿￿
L	e	voltage	signal
mod		een
			&	A/D board
	betw
		source

G N D

C H IN

+

In p u t

LL G N D

I/O

C o n n e c to r

A m p

-

To A /D

W h en the voltage difference betw een signal source and A /D boa rd ground is large enough so the A /D board ’s com m on m od e range is exceeded, isolated sig nal conditioning m ust be add ed.

A /D Board

System w ith a Large C om m on M ode Voltage, Connected to a Single-Ended Input

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