Research Concepts RC2000A User Manual

Page 76

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76

RC2000A Dual Axis Antenna Controller

Appendix E

Communications Protocol

bytes 7-16 : This field will contain the satellite
name.

byte 17 : ETX
byte 18 : 'chksum' the checksum

Note that if entry 'XX' does not exist in the list (or the list
has no entries) the NAK reply will be sent back to the host. */

/* AUTO MOVE COMMAND **

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 specified for 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.

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

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