1 search sub-mode, Search sub-mode – Research Concepts RC2500 User Manual

Page 49

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42

RC2500 Antenna Controller

Chapter 5

Modes

Research Concepts, Inc. • 5420 Martindale Road • Shawnee, Kansas • 66218-9680 • USA

www.researchconcepts.com

Whenever the 'IDLE' message is displayed on the bottom row of the display:

• The current time is displayed in an hours.minutes format (00.00 to 23.59),

• The '0-MENU' message will be displayed to the right of the time display if expert access

is enabled via CONFIG mode, and

• the POL CCW, POL CW keys may be used to adjust the polarization if remote mode has

been disabled. Also if the Pol equipment code has been set to 1, the H, and V keys will

rotate the polarization axis to the given pre-stored position.

The '0-MENU' display indicates that the user can hit the 0 key to activate the TRACK mode menu. From

the TRACK mode menu the user can view the contents of the track table, see the current sidereal time

and the scale factors for the satellite currently being tracked, modify certain track parameters, and initiate

certain track operations. See section 5.4.5 for a description of the TRACK mode MENU system.

If TRACK mode receives control via SETUP mode, the controller will perform some data initialization and

then switch to the STEP track sub-mode. A SYSTEM error may be detected during the initialization.

These are described in Chapter 7 - TRACK Mode Errors.

If TRACK mode receives control via AUTO mode, the controller will check for the presence of track table

information for the current sidereal time. If track table information is found, the controller will activate the

PROGRAM track sub-mode. If track table information is not available, the SEARCH sub-mode will

receive control.

5.4.1 SEARCH Sub-mode

The following conditions lead to activation of the SEARCH sub-mode:

1. TRACK mode is entered from AUTO Mode and program track data is not available in the track table

for the current sidereal time;

2. the STEP TRACK sub-mode is active and the satellite transponder goes down;

3. or PROGRAM TRACK mode is active, and the AGC inputs indicate that a satellite signal is not

present when the sidereal time advances to a value for which track data is not available in the track

table.

The behavior of the controller when the SEARCH sub-mode is active is determined by the state of the

Search Enable CONFIG mode item. If Search is disabled, when the SEARCH sub-mode activates, the

controller will prompt the user to manually align the antenna with the satellite (by using the jog keys) and

hit the ENTER key to transfer control to the STEP TRACK sub-mode. If the sidereal time advances to a

value for which track data is available in the track table, control will transfer to the PROGRAM TRACK

sub-mode.

If the Search Enable CONFIG mode item is enabled, the controller will perform a search for the satellite

using the Intelli-Search algorithm. When the search is performed, the controller will sweep the antenna in

a serpentine shaped pattern over the region where it has calculated the satellite will be found. The width

of the search box is controlled by the Search Width CONFIG mode item. If during the search a signal is

detected above the appropriate AGC threshold (either C or K/L) the antenna will return to the position

where the signal was detected and control will transfer to the STEP TRACK sub-mode. If the search is

unsuccessful, the controller will wait for Search Retry minutes before initiating another search. The

Search Retry parameter may be inspected and modified via the TRACK MENU - Modify menu.

Additional information concerning the Search sub-mode is available in section 4.2.3. Note that for

transmit applications it is generally advisable to disable the automatic search feature.

When the SEARCH sub-mode is active, the following messages will be displayed to the right of the

satellite name on the bottom row of the display.

SEARCH - A search is in progress. If a satellite is found, the STEP track sub-mode activates.

SEARCH IDLE - A search has been performed and a satellite was not found. The controller is waiting to

perform another search. The TRACK MENU function may be invoked to initiate another search, or to

change the Search Retry Interval. If the sidereal time advances to a value for which track table data is

available, the PROGRAM track sub-mode will activate.

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