Sea Tel 9711-92, Installation And Operation Manual

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9711-92 Ku-Band TXRX Installation
3-31
3.6.7.4. TS1 Control Interface Connections.
AGC & GND - External AGC, or Modem Lock, input.
•
External AGC input to the DAC-2202 must be 0 to 15 Volts DC analog signal, positive going voltage proportional
to satellite signal input level and must be real-time in its
response to antenna pointing.
•
External Modem Lock from a satellite modem is used as
a positive ID that the antenna is on the desired satellite.
This input is NOT used for Tracking purposes
, it is
only used for satellite identification to acquire the
correct satellite during search. To enable the external
modem input you must include a 2 in the SYSTEM TYPE
parameter (If your system type is presently 76 or 77,
then change it to 78 or 79) and
NID MUST be set to
0000 .
•
Connections - The modem lock signal connects to
EXT AGC and 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).