C-COR NA15T Series Procedures Manual - Table 5.
MX0860
Revision B
Transmitter Controls and Indicators 17
Table 5.
Transmitter Controls and Indicators
Item
Label
Function
1
STATUS
LED
LED lights green to indicate that RF is present and that the transmitter is
functioning normally with laser active.
LED lights yellow (Minor Alarm) to indicate a parameter that will not cause
damage or affect operation of the transmitter, but may be near an operational
limit.
LED lights red (Major Alarm) to indicate a parameter that could affect the
operation of the transmitter.
Alarms are generated for Laser Temperature, Laser Bias Current, Laser Cooler
(TEC) Current, Manual Shutdown State, Keyswitch state. The transmitter will
shut down under certain conditions. After shutdown, the transmitter may
power up again if the monitored values return to normal.
2
LASER
keyswitch
ON
position—Laser is enabled when the key is turned to this position. The
STATUS
LED will flash yellow for a few seconds when keyswitch is turned,
indicating the laser is not in a steady state.
OFF
position—Laser is off—Yellow
STATUS
LED should not be lit.
3
MOD ADJUST
Allows adjustment of the RF signal level of carriers before they are modulated
onto the optical fiber(s) when the unit is in
MANUAL
mode. Pressing the
recessed ▲ and ▼ buttons, raises or lowers the RF signal level by ~0.25 dB
for each press of a button. The recessed
RESET
button resets the modulation
index back to the default, factory-preset level.
The LED panel at the left shows the amount of change in LED segments that
each indicate ~0.5 dB of signal change. Illuminated segments above the center
markings indicate a setting above the preset level. Illuminated segments below
indicate a setting below the preset level. Refer to Section 10.2 for information
on distortion effects when adjusting RF Modulation.
4
MANUAL
LED
LED lights when in Manual mode. Manual mode provides a constant gain. In
Manual mode, the modulation index can be adjusted with the
MOD ADJUST
controls.
5
CW
LED lights when in Continuous Wave (CW) mode. CW mode sets up an
appropriate RF level for the number of carriers specified on the specification
sheet. When different channel loads are applied to the unit, the Automatic
Gain Control (AGC) maintains constant total band power (meaning fewer
carriers will cause the AGC to increase the carrier amplitude of the remaining
channels to maintain the same total amount of power). This mode is normally
used for certain FCC tests and to manually verify that performance is within
specified limits.
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