GPX Pro Manual28
© 2009 XT Racing
coordinates which determine the lap and split times. Y can capture RPM, gear, suspension, and
other inputs from your racing vehicle.
NOTE: throughout this manual, the words input and channel refer
to one and the same thing.
Cabling and Electrical Information
There are two sets of expansion cables supplied with the GPX Pro, labeled “A” and “B”. If you use
these expansion cables, make sure that you plug the “A” cable into the “A” connector and the “B”
cable into the “B” connector.
NOTE: For each cable you connect to your vehicle, make sure that
the black wire is well fastened to the vehicle’s
“ground” (essentially the negative terminal of the battery). If
direct connection to the battery is not feasible, you may connect it
to the metal chassis as long as a good electrical connection is
made from the black wires to the chassis, and the chassis has a
good electrical connection to the vehicle’s negative battery
terminal.
12V Power
You may connect the GPX to the 12V power (essentially, the positive terminal of the vehicle’s
battery). This is done with the RED WIRE OF CABLE “A”. If you connect to the vehicle’s 12V, then
the GPX will always be powered by your vehicle. (The internal battery will be continuously
charged.) So that the GPX does not drain the vehicle’s battery when the vehicle is turned off, it is
preferable to connect the 12V power wire to the GPX via a switched power point so that when the
vehicle is turned off, the 12V is not supplied to the GPX. If this is not feasible, it is recommended
that you disconnect CABLE A when you are done racing.
Analog vs. Digital Signals
Analog signals typically have a range of from 0 to 5 volts. These signals generally can have any
value in that range. Typical examples of analog inputs would be engine coolant temperature,
suspension via linear potentiometers, or throttle position. In addition, a switch input (on/off
type of signal) (e.g., idiot oil warning light) may be connected to any of the analog inputs.
Digital signals are pulsed inputs (e.g., RPM or wheel speed sensor). The GPX can handle digital
signals which have swings in the 0-5V range to signals with swings in the 0-12V range.
GPX DAQ Inputs
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