Chapter 5: Accessories
Wiring Vehicle Power to the VH10
131
Psion VH10 Vehicle-Mount Computer User Manual
5.7.3.2
Power On/Off with Ignition Option: Wiring
This ignition detection application puts the VH10 into Suspend when the vehicle ignition is turned off, and
powers the VH10 on when the ignition is turned on. You can enable this feature and set a delay time for the
VH10 to go into Suspend. When a delay time is specified, a window appears on-screen at the time of ignition
off. This window shows the time countdown, and contains power-off-now and cancel buttons. The window is
shown on top of any running application, attached to the right side of the screen, and may be repositioned
by dragging it up and down as desired.
•
In the
Control Panel>Power Properties
dialog box, open the
Advanced
tab.
For Ignition Detect to be available, appropriate wiring must be installed (see Figure 5.23 on page 130: “Con-
nections To Vehicle DC Supply”). The Ignition Detect application receives the ignition signal from a vehicle.
The Ignition Detect signal is transmitted through the existing 4-conductor CPC power cable. On detection of
the ignition signal, the vehicle-mount computer resumes or boots up and goes into suspend when the
signal is dropped.
The diagram in Figure 5.24 on page 132 shows the extension cable kit (P/N 13985-301) with the two smaller
wires used to connect to the vehicle ignition. The red and black leads of the two wires connect to the key
switch of the ignition and the ground, respectively. Once these wires are connected, the VH10 will be
switched on or off depending on the state of the vehicle's ignition key.
Note: This feature does not interfere with other methods of turning the computer off and on.
Important: If your vehicle was wired for a previous generation vehicle-mount computer and was
using the screen blanking feature, please ensure that you are no longer feeding the
screen blanking signals to the VH10's main CPC power cable since these two signals are
now being used for Ignition Detect.
Unlike the screen blanking cable, the two ignition detect input terminals are not shorted
to signal the ignition state. Instead, a positive voltage should be applied to the Ignition
Detect Input (+) terminal. The voltage of the signal can be as high as the allowed exter-
nal DC input voltage (between 12VDC to 48VDC nominal). In addition, you must connect
the Ignition Detect Input (-) to the corresponding ground reference.
Important: When connecting to an ignition switch using the extension cable (PN 13985-301), make
sure the wires of different polarities are reliably secured away from each other, or are
separated with reliably secured certified insulation. A minimum distance of 2.8mm
(or 0.4mm distance through insulation) is required for the separation.
It is recommended that the ignition connecting cables be protected by a fuse of the fol-
lowing type: 5x20mm T 125mA L/250V, for example, a Wickmann 195-125mA/
250V fuse.
