ADLINK PCI-9524 - Manual (Page 50)

34 Signal Connections
PCI-9524 ADLINK Technology Inc.
User’s Manual Copyright 2008
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-
NC
NC
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
using when connecting to the transducer. A lengthy extension
cable between PCI-9524 and the terminal board inevitably has
some lead resistance that results in voltage drop; looping-back the
excitation on the terminal board creates a six-wire connection and
compensates for voltage drop.
A better approach is to use specially designed load-cell transduc-
ers having two additional SENSE terminals. The voltage difference
across the bridge excitation junctions is fed back to the voltage
excitation circuitry by two separate 'sense-wires', to further correct
the voltage drops due to the resistance in the excitation wiring. Be
sure to enable the remote-sense function to take full advantage of
a six-wire connection. A typical six-wire connection is shown in
Figure 3-5.