HT-4600/PB-4600 series Technical Manual 29
SOFTWARE SWITCH OFF
An easy method for software control to turn the system off is the software off switch.
This function can be very useful in unattended application. The hexadecimal
command string for software switch off function is : <06> <16> <19> <1D> <n>.
In the above, the “n” indicates the time delay in seconds for actual power off after the
command string given to COM1. However, an alternative command string <1B> <00>
<00> <00> <00> <00> <00> <00> can be used instead to turn off the system power
immediately.
Some operating system or software may require complete termination of application
programs before system power off for the sake of system maintenance. In that case the
programmer has to program the command to close the application programs (just like
“Alt+F4” in Windows), and then at the end of the closing operation, the application
program should issue the above mentioned software switch off command string to
COM1 under the protocol: 9600 bps, parity none, 8 data bits, 1 stop bit.
FORCED SWITCH OFF
In case of serious system halt due to system resources conflict or any reason, the
system could fail to power off through normal means. The Forced Power Off method
is designed for such occasions. With the external power switch defined as power
ON/OFF switch (default status), push down and hold this Power ON/OFF Switch. The
system will be powered off within 10 seconds in this way. Whenever the machine
receives a software command to change the external power switch to ON only, the
forced power off function is disabled. However, an enhance power off command is
provided for the software programmer to allow forced power off after changing the
switch to be ON only. The enhance forced power off command string is <1B> <00>
<00> <00> <00> <00> <18> <18> and it has to be sent in same way like the ON only
switch command. This enhanced forced power off requires the user to keep the switch
pressed for a longer period between 10 to 20 seconds to function.
In case the system halt situation is so serious that some hardware/firmware
registrations are already confused, this above-mentioned forced power off could