System Global Variables - Metrologic Optimus S Programming Manual

24 "C" Programming Guide For Optimus S/R

3.1.3 System Global Variables

There are several global variables that are declared by the system.
Two of them are system timers that are cleared to 0 upon powering up.
extern volatile unsigned long sys_msec;
extern volatile unsigned long sys_sec;
Note: Do not write to these system timers as they are updated by the timer interrupt.
Other system variables are as follows.
extern unsigned int
This variable governs the timer for the system to automatically shut down the user's
program whenever there is no operation during the preset period.
When it is set to 0, the AUTO_OFF function will be disabled.
extern unsigned int
This variable can be set to either POWERON_RESUME or POWERON_RESTART.
By default, it is set to POWERON_RESUME, i.e., upon powering on, the user program
will start from the last powering off session.
However, in some cases the user program will always restart itself upon powering on:
extern unsigned int
This variable holds the backlight timer for the LCD when its backlight is set on. By
default, it is set to 20 seconds.
AUTO_OFF;
POWER_ON;
when batteries being removed and loaded back;
when entering the System Menu before normal operation.
BKLIT_TIMEOUT;
/* in units of 5 ms */
/* in units of 1 second */
/* in units of 1 second */
/* in units of 1 second */