BERKSHIRE PRODUCTS PC Watchdog, Hardware Manual, Page: 8 / 19

3. Dip Switch Settings
All the switches are read at power up and after each time that the Watchdog resets the PC. A switch
that is
DOWN is OFF and a switch that is UP is ON . The following sections cover the switch options.
Switch Description
1 Enable Passive Mode
2 Enable Active Mode
3 Disable Buzzer
4 Temperature Reset Enable
5 Power On Delay
6-8 Watchdog Delay Time
3.1 Mode Switches - SW1 & SW2
These two switches set the operating mode of the Watchdog. If both of these switches are off then the
Watchdog powers up in factory diagnostics mode and will not operate properly!
It is OK for one or both of these switches to be on at one time. The Watchdog will support both modes
together.
3.2 Switch #1 - Passive Mode
When this mode is active the Watchdog will monitor the USB for a 32mS polling (interrupt) packet
from the host PC. Each packet will cause the Watchdog to reset its timeout count. If the PC locks up
and the packets stop then the Watchdog will count down to zero and reset the PC.
We recommend that
you no longer use this option. There is a program on the CD that will “tickle” the board in Active
Mode.
3.3 Switch #2 - Active Mode
If this switch is on the Watchdog enters command mode. This requires that the PC send commands to
the Watchdog as USB data packets to make it reset the timeout counter. Commands can be sent with
the BPI_WDog_Tickle program and with a user application program using the DLL.
3.4 Switch #3 - Buzzer Disable
If this switch is on the buzzer will be disabled. The buzzer can also be disabled with software options.
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