
SYS-405/Configuration
v1.0
www.winsystems.com
Page 10
Top View Switches
The following table provides switch descriptions and references for the figure on page 8
(“Top View Components”).
BAT1/BAT2
The SYS-405 uses a single CR-2032 or CR-2025 battery. The nominal voltage of either
battery is 3.0 V. This battery, or alternatively an external battery connected to the SYS-
405 board, provides standby power for the real-time clock and optional GPS. See
“Battery Select (JP3)” on page 28 and “External Battery Connector (J7) (Optional)” on
page 17 for more information.
8.2 Power
The SYS-405 draws power through the J5 connector (see “Power Input (J5)” on
page 16). The main supply to the board is +10-50 V DC.
8.3 Watchdog Timer
The SYS-405 features an advanced watchdog timer (WDT) that can be used to guard
against software lockups. The timer is programmable from 1 second to 255 minutes.
NOTE
Use a long timeout if the watchdog is enabled when trying to boot any operating
system.
The watchdog can be enabled, disabled, or reset by writing the appropriate values to the
configuration registers. The WDT is part of the embedded controller, which uses the
following command sequence:
CMD Register:
0x66
Read Command:
0x80
Write Command:
0x81
Sync Command:
0x82
DATA Register:
0x62
Item
Description
Reference
SW1
Power Button
page 30
SW2
Reset Button
page 31