Psion Teklogix Vehicle-Mount Computer 8590 - Manual (Page 146)

Chapter 8: Internal Devices
Automatic Shutdown Process
120 8580/8590 Vehicle-Mount Computer User Manual
Heating is required if you want to operate the 8580/8590 at ambient temperatures
below 0 C.
In the following two sections, the main functions of the automatic heating and
shutdown modules are described. For detailed information on the automatic
shutdown and heating modules - complete with pre-defined thresholds - refer to the
program flowchart diagrams (part 1 and 2) below.
Resources
The automatic switch-off/heating module requires the COM3 port for configuration.
In normal use the LPT1 port is used for communication.
8.6.1 Automatic Shutdown Process
When the ignition is switched on, the 8580/8590 is supplied with power and begins
checking its internal temperature and automatic shutdown function.
Once the ambient conditions have been verified as acceptable, the 8580/8590 starts
the operating system just like normal.
During the first three minutes of the start-up phase, none of the ambient conditions,
such as the internal temperature or the Ignition input status, are checked. This allows
the operating system and the operating software for the automatic shutdown module
to fully load without interruption. Following this three-minute period, the internal
temperature of the unit and the status of the Ignition input are checked continuously.
If the inner temperature of the 8580/8590 reaches a critical range, the operating
system is shut down normally and the computer remains switched off until the
temperature is back in the permitted range.
If the Ignition input is switched to earth potential or a potential-free source during
normal operation, the unit switches to shutdown delay time. In this state, the device
continues to operate normally until the delay time (for example, 15 minutes) has
elapsed.
• If the ignition is triggered again during this time, the 8580/8590 resumes
normal operation.
• If, however, the delay time elapses, the operating system is shut down nor-
mally by the 8580/8590 operating software and the unit is automatically
switched off (for example, after three minutes, or after a signal from the
operating software).