Operating Instructions
Remote interface
3
Table 3-1. Environmental Monitor Connector Signals
Pin
Number
1, 8
2, 7
3, 6
4, 5
3-8
The remote interface is designed to interconnect with an
environmental monitor I/O port on the host computer. Each pin
connection, signal mnemonic, and signal characteristic for the
connector is listed in the following table.
Signal
Mnemonic
SVCCFAIL
Active-low output from SCSI backplane indicating a DC
power problem. SVCCFAIL activates if the +5Vdc
power supply output falls below 0.5 volts.
In installations with multiple peripheral expansion
enclosures, any enclosure on the environmental monitor
bus can pull SVCCFAIL down to its active low state.
Check the power-on LEDs on the drives to identify the
faulty unit.
DISKOT
Active-low output that illuminates the Overtemperature
LED to indicate a cooling problem. Activates at a slightly
lower sensor temperature than cooling failure shutdown,
so that system operation can continue if the problem is
corrected promptly.
GND
Signal return path.
DCEN
Open-collector active-low input from host. When low,
remotely enables the XR900 power supply (i.e., the
power supply turns on if the SCSI TERMPWR signal is
present). When high, disables the XR900 power supply.
When open, passes control of the power supply to the
SCSI TERMPWR signal.
Signal Name and Description