Sea Tel 4009-9 BROADBAND-AT-SEA, Руководство по установке

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4009-9 Installation Manual Installation
3-16
a GND reference from the modem. The expected signal from the modem allows 0VDC
to +15VDC. Low voltage indicates modem lock, high voltage indicates modem unlock.
•
Testing - The input connections from the modem can be tested by selecting the
external AGC input and monitoring the displayed value. To select external AGC, set the
tuning frequency to 0000. Normally, AGC readings below 2048 are considered a low
condition and indicate modem lock and AGC readings above 2048 are considered a
high condition and indicate modem unlock.
[If you find the AGC reading for locked and unlocked conditions need to be reversed you must
add 128 to your current SYSTEM TYPE parameter].
Turn tracking OFF when checking the external AGC inputs. Be sure to properly retune the
receiver frequency when you are finished testing the external input.
•
Operation - In NORMAL operation, AGC must be above Threshold AND external
MODEM Lock input must be locked to Track the satellite. If you are tracking a satellite
signal and the AGC is above threshold (Tracking light on solid) but the external AGC
signal rises above 2.5 volts for more than 20 seconds (external MODEM input
UNLOCKED) the ACU will automatically retarget the selected satellite.
SW1 - Band Selection control output. This output is used to control below decks tone
generator(s), or coax switch(s), for band selection functions. The band selection control output
is driven by the band selected in the MODE – TRACKING display.
SW2 - The Blockage
/ TX Mute Control output is driven by Blockage and RF Radiation Hazard
functions. This output will short to ground whenever the antenna is within the programmed AZ
LIMIT zone(s) or is Searching, Targeting or is mispointed 0.5 degrees from satellite peak. This
output is commonly used to drive:
If your modem cannot use the Modem Console Port connection you will have to provide a
transmit inhibit output from the ACU by connecting a SW2 wire connection to the modem
to comply with FCC Order 04-286 and WRC-03 Resolution 902
.
• Dual or Quad Antenna Arbitrator coax switches in dual antenna configurations. The
coax switches select which antenna is feeding signal to the below decks equipment.
• Mute the Transmit output of the Satellite Modem used in TX/RX antenna
configurations when the antenna is positioned where people may be harmed by the
transmit power emanating from the antenna (RF Radiation Hazard).
•
Mute the Transmit output of the Satellite Modem used in TX/RX antenna
configurations when the antenna is mispointed by 0.5 degrees, or more, and keep it
muted until the antenna has been within 0.2 degrees of peak pointing to the satellite
for a minimum of 5 seconds (FCC part 25.221 & 25.222 TX Mute requirement).
3.7.7.5. TS2 Synchro Gyro Compass Input.
Use the R1, R2, S1, S2 and S3 screw terminals to connect the Synchro Gyro Compass to the ACU.
3.7.7.6. TS3 Step-By-Step (SBS) Gyrocompass Input.
Use the COM, A, B and C screw terminals to connect the SBS Gyrocompass to the ACU. Some
SBS Gyro distribution boxes have terminals which are labeled S1, S2 & S3 instead of A, B and C.
3.7.7.7. TS4 Power
• VREG Screw terminal is used to provide a regulated DC operating voltage to ancillary
equipment. Voltage out is dependent upon which terminal mounting strip assembly is
provided. 126865-1 supplies 8Vdc @ 1Amp, while the 126865-2 assembly supplies 5Vdc
@ 2Amps.
•
GND Screw terminal is the ground reference for the regulated and unregulated power
terminals.