Manual PCI-WDG-CSM
13
Input/Output Connections
Connections are made via a 25-pin FEMALE connector on the card mounting bracket. Also, there are
either one or two, three-terminal blocks, and one four pin header for connecting to the reset line or power
good line, or other functions, depending on the options purchased. Signal assignments are listed in
Chapter 6 of this manual.
To ensure that there is minimum susceptibility to EMI and minimum radiation, it is important that the card
mounting bracket be properly screwed into place and that there be a positive chassis ground. Also,
proper EMI cabling techniques (cable connect to chassis ground at the aperture, shielded twisted-pair
wiring, etc) be used for the input/output wiring.
Connecting the Reset Line
If your computer is equipped with a reset button you must connect reset button wires across the “C” and
“NC” header at the top rear edge of the Watchdog card as shown in figure 2-1. Install the “ON/EN” jumper
on the Watchdog card in the “EN” position. Then using the cable connect the second set of “C” and “NC”
header pins to the Reset pins on the mother board. The hot side of this connection must be connected on
the “NC” side of the header. You can determine which reset push button wire is hot by removing the reset
pushbutton connector from the motherboard and measuring for +5VDC on the pins. Alternatively, you can
try to connect into one wire, running the sample program, and if it doesn't work, try connecting to the
other wire.
If there is no reset push button and your computer is equipped with an ATX power supply, connect the
power good line to the “NC” header pins on the Watchdog card as shown in figure 2-2. To make a
connection, insert the cable into the clamp, compress the metal bar with pliers and close the protective
cover. Install the “ON/EN” jumper on the Watchdog card in the “EN” position. Then install a jumper on the
“GND” header on the Watchdog card.
If there is no reset push button and your computer is equipped with an AT-type power supply, you can
connect the power good line on P8 of the Mother Board to the /WDRST terminal of the watchdog card as
shown in figure 2-3, or connect the power good line to the “NC” header as shown in figure 2-2. Note: If
the “NC” header is used ensure that a jumper is installed on the “GND” and the “EN” headers on the
Watchdog card.
C
NC
GND
ON
EN
RELAY
To Motherboard
Reset Pins
From Reset Button
CAB-WDG-RST
Figure 2-1:
Reset Button Connection
