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

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Setup – Blockage & RF Radiation Hazard Zones 4009-9 Installation Manual
11-1
11. Setup – Blockage & RF Radiation Hazard Zones
This section discusses how to set up blockage, or RF Radiation Hazard, zones.
11.1. Radiation Hazard and Blockage Mapping (AZ LIMIT parameters)
The ACU can be programmed with relative azimuth sectors (zones) where blockage exists or where transmit
power would endanger personnel who are frequently in that area. Your ACU software may allow you to set four
zones or it will only three zones and i5 volt polarization.
When the AZ LIMIT parameters are set to create these
ZONES (up to four), several things happen when the
antenna is within one of the zones:
1. Tracking continues as long as the AGC value is greater than the Threshold value. When the AGC value
drops below Threshold, the antenna will wait “Search Delay” parameter amount of time and then re-
target the satellite you targeted last (if 4 value is included in SYSTEM TYPE). Timeout and re-target will
continue until the satellite is re-acquired and tracking can resume.
2. “BLOCKED” will be displayed in the TRACKING window wherever the antenna is inside one of the zones.
3. A contact closure to ground (or an open if the blockage logic is reversed – See SYSTEM TYPE 16 value) is
provided on the SW2 terminal of the Terminal Mounting Strip. This Switch output provides a “Blocked”,
“RF Radiation Hazard” or “FCC TX Mute” logic output. When the antenna exits the zone it will be on
satellite, tracking and the SW2 logic contact closure will open.
The lower and upper limits are user programmable and are stored in NVRAM within the ACU parameter list.
AZ LIMIT 1 is the Lower Relative AZ limit (this is the more counter-clockwise of the two points, even if it
is numerically larger). AZ LIMIT 2 is the Upper Relative AZ limit (the more clockwise of the two points)
for pattern mapping of ZONE 1. Enter the elevation value that represents the top of the blockage
between the two azimuth limit points in the EL LIMIT 12 parameter.
AZ LIMIT 3 is the Lower Relative AZ limit (CCW point) and AZ LIMIT 4 is the Upper Relative AZ limit (CW
point) for pattern mapping of ZONE 2. Enter the elevation value that represents the top of the blockage
between the two azimuth limit points in the EL LIMIT 34 parameter.
AZ LIMIT 5 is the Lower Relative AZ limit (CCW point) and AZ LIMIT 6 is the Upper Relative AZ limit (CW
point) for pattern mapping of ZONE 3. Enter the elevation value that represents the top of the blockage
between the two azimuth limit points in the EL LIMIT 56 parameter.
AZ LIMIT 7 is the Lower Relative AZ limit (CCW point) and AZ LIMIT 8 is the Upper Relative AZ limit (CW
point) for pattern mapping of ZONE 4. Enter the elevation value that represents the top of the blockage
between the two azimuth limit points in the EL LIMIT 78 parameter. If your ACU software includes 5 volt
polarization you will not see these AZ & EL LIMIT parameters.
CAUTION: The Lower Relative AZ limit is the more counter-clockwise of the
two points (even if it is numerically larger) and the Upper Relative AZ limit is
the more clockwise of the two points. If you enter the two relative points
incorrectly, Tracking and Searching will be adversely affected.
The ACU provides a contact closure to ground on the SW2 terminal of the Terminal Mounting Strip when the
antenna is pointed within any one of the blockage/hazard zones or the system is searching, targeting, unwrapping
or is mis-pointed by 0.5 degrees or more (FCC TX Mute function for Transmit/Receive systems only). The contact
closure is a transistor switch with a current sinking capability of 0.5 Amp. Refer to “Functional Testing” for
instructions on how to simulate a manual BLOCKED condition to test SW2 logic output.
When used as simple “
BLOCKED ” logic output for a single Sea Tel antenna, this output could be used to light a
remote LED and/or sound a buzzer to alert someone that the antenna is blocked, and therefore signal is lost.