OPTICAL SYSTEMS DESIGN
DOC ID: 10112902
OSD350B OPERATOR MANUAL
PAGE 3
3
INSTALLATION AND OPERATION
3.1
OSD921 POWER SUPPLY OPERATION
The OSD350B can use up to two OSD921 power supply units.
A front panel mounted LED indicator on the OSD921 illuminates when the power supply unit is
switched on. Front panel test points are available on the OSD921 for monitoring the 12VDC output
of the supply. Note that the test point outputs are current limited and cannot be used as a power
source.
The OSD921 supply has a built-in cooling fan.
The cooling fan operates only when high temperatures are experienced on the power supply whilst
under heavy load and/or high ambient temperatures.
The fan may not continuously operate and under low load or low ambient temperatures it may not
operate at all.
The
Temperature Alarm
LED on the front panel of the OSD921 is green during normal operation
and will be red when the operating temperature exceeds the normal operating limits of the supply.
Do not continue to operate the power supply when the Temperature Alarm LED is red and take steps
to rectify the cause of the excessive high temperature indication.
3.2
IMPORTANT INSTALLATION REQUIREMENTS
It is important to provide a cool operating environment as well as to provide adequate ventilation.
The OSD350B chassis must be separated by at least a 1RU (about 44mm) gap above and below
the unit to provide ventilation.
The ventilation holes of the chassis must never be covered by any objects.
3.3
BACK PLANE OUTPUTS
The OSD350B is merely a mechanical chassis, so electrical specifications are not given, other than
the pin outs for the 9-pin D female connector of the back plane.
DB9 Pin
Specification
1
NMS Address Bit 1
2
NMS Address Bit 2
3
+12V
DC
nominal
4
NMS Address Bit 3
5
D+
6
Ground
7
Ground
8
NMS Address Bit 4
9
D-
