Chapter 1
Using the Mainframe
1-6
www.ni.com
ACFAIL*
This pin lets you monitor the ACFAIL*
signal from the backplane. Because this
pin is connected directly to the backplane,
do not violate VXI backplane electrical
specifications (that is, keep the cable as
short as possible or buffer the signal,
etc.).
EXHAUST_TEMP
This pin provides an analog output that is
proportional to the power supply exhaust
temperature. Using this circuit, you can
monitor the actual temperature of the
power supply exhaust temperature to
receive a warning signal that the
mainframe is running under abnormal
conditions. This output provides 0 VDC
at 0 °C, with a rise of 10 mV per degree
centigrade when referenced to chassis
ground.
Remote Standby Switch
The remote standby switch connection lets you turn the mainframe ON or
put it in STANDBY mode remotely. These two connections are wired in
parallel with the front panel ON/STANDBY switch. The front panel switch
must be in STANDBY position for the remote switch to function correctly.
Figure 1-3. Remote Standby Switch Wiring