Research Concepts RC2000C - Manual (Page 98)

90 RC2000C Az/El Tracking Antenna Controller Appendix E Communications Protocol
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This command causes the controller to automatically position the antenna in either azimuth and
elevation and/or polarization. The command has 3 forms.
Form 1. If the sat_name/position field contains the name of a satellite saved via the controller's SETUP
mode the controller will position the antenna at the azimuth and elevation positions associated with that
satellite. The satellite name should be in capital letters, left justified and padded on the right with blanks
in the sat_name/position field. Note that the satellite name must exactly match one in the controller's
non-volatile memory.
With this form of the command, the polarization field may contain either 'H', 'V', or ' ' (a blank, 20 hex or
32 decimal). If an 'H' or a 'V' is specified, in addition to positioning the antenna in azimuth and
elevation, the polarization control device will be commanded to go to the position associated with either
the horizontal (if 'H' is specified) or vertical (if 'V' is specified) polarization associated with the satellite. If
the field contains a blank the polarization is not changed. For example, this command with 'H' in the
polarization field and 'SBS 6' in the sat_name/position field will specify an auto move to SBS 6 and the
polarization will be adjusted to horizontal for the SBS 6 satellite.
Form 2. If the sat_name/position field contains a valid pair of azimuth and elevation positions the
antenna will move to the position specified. The first 5 characters of the sat_name/position field specify
the azimuth position (azimuth sub-field) and the last five characters specify the elevation position
(elevation sub-field). Within each of the sub-fields the position must be right justified and left padded
with zeroes. For example, a sat_name/position field value of '0152500750' specifies an azimuth
position of 1525 counts and an elevation position of 750. For the command to be accepted these
positions must be within their respective limits for each axis. For this form of the auto move command,
only the blank character is accepted in the polarization field. Note that the position must be specified in
position counts and not in an angle format.
Form 3. If the polarization field contains the 'P' character, the command is interpreted as a
go_to_polarization command. For this form of the command, the first 5 characters of the
sat_name/position field specify the target polarization position in the controller's internal polarization
position representation (polarization sub-field). See byte 32 of the device status poll reply for more
information on the internal polarization position representation for the different types of polarization
control devices. The polarization position in the polarization sub-field must be right justified and left
padded with zeroes. The second 5 characters of the sat_name/position field must contain '00000'. For
example, if the sat_name/position field contains '0050000000' the polarization control device is
commanded to adjust the polarization to a position of 500.
The command contains 16 bytes. Here is the format;
byte 0: STX
byte 1: A where A is the RC2000 address
byte 2: 32h the auto move command code
byte 3: polarization This field can specify 'H', 'V', ' ' (blank), or 'P'.
byte 4-13: sat_name/position
This field specifies the satellite name or a target azimuth and
elevation or polarization position.
byte 14: ETX
byte 15: checksum
The normal reply to this command will be the same as the reply to the status poll query except that the
command code field will be '32h'. The NAK reply will be sent to the host if … a) the satellite name is not
found in non volatile memory. b) the Auto Pol system is enabled and the command specifies
polarization movement (byte 3= ‘H’, ‘V’ or ‘P’ or c) the position specified for form 2 or 3 of the command
is outside of the position limits for that axis.
AZIMUTH/ELEVATION JOG COMMAND
This command jogs the antenna in azimuth or elevation. The command contains 11 bytes. Here is the
format of the command;
byte 0: STX