User`s manual

34 Signal Connections

PCI-9524 ADLINK Technology Inc.

Floating Signal Sources

A floating signal source is not connected in any way to the build-

ings ground system. A device with an isolated output is a floating

signal source, such as optical isolator outputs, batteries, trans-

former outputs, load-cells and thermocouples.

3.2.2 Input Configurations

Differential input mode for transducer input channels

AI channels 0 to 3 are dedicated to connecting to load-cell trans-

ducers in differential mode.

A load-cell is comprised of four resistive strain-gauges connected

in Wheatstone bridge form, and is inherently a floating differential

output device. Since a load-cell transducer is a passive device, it

requires voltage excitation in order to transform the resistive

change into electrical signals. A typical four-wire connection is

shown on Figure 3-4.

Figure 3-4: Connecting to a four-terminal load-cell transducer

using a four-wire connection

+Vex

+Vo

-Vex

-Vo

AIn+

AIn-

VEXn+

VEX_SENn+

VEXn-

VEX_SENn-

Load-cell Transducer PCI-9524

It is recommended to enable the remote-sense function, and loop-

back the VEXn+/- to VEX_SENn+/- on the terminal board you're