RESEARCH CONCEPTS RC2000C Manual page 90

84 RC2000C Polar Tracking Antenna Controller
byte 33:
7 6 5 4
- - - -
0 1 b1 b0 $
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internal_position = ((byte_24_25_position * 661) / 99) +
ls_nibble_byte_32
where ...
internal_position ... is the controller's internal Polarotor position
representation.
byte_24_25_position ... is the Polarotor position reported via byte 24
and 25 of the device status poll reply and displayed on the user
interface (a value in the range of 0 to 98).
ls_nibble_byte_32 ... is the least significant nibble (lower 4 bits) of this
byte.
Note that in the above equation the division is an integer division which
means that the result of the division should be rounded DOWN to the
closest integer value (i.e. (39 * 661) / 99 = 260).
When a Polarotor is present in the system the upper nibble of byte 32
will be '0010'.
For the rotating feed, the internal polarization position and the
polarization position displayed via the user interface are the same and
will be a value in the range of 0 to 1023. For the rotating feed the user
is prompted to set CW and CC limits. When the polarization position is
less than or equal to the CW limit specified by the user the 'CW'
banner will be displayed. When the polarization position is greater
than or equal to the CC limit specified by the user, the CC banner will
be displayed.
The polarization position given by bytes 24 and 25 of the device status
poll reply will be a value in the range of 0 to 92. When the rotating
feed is at a limit (or beyond) the byte 24,25 values will be 'CW' or 'CC'.
To obtain the internal polarization position for the rotating feed from
this byte and the value in bytes 24 and 25, use the following formula ...
internal_position = (byte_24_25_position * 11) + ls_nibble_byte_32
where the variables are as defined for the Polarotor case. Note that
when a rotating feed is present in the system, the upper nibble of byte
32 will be '0011'.
Track Mode submode or error status and track frequency band.
$ 3 2 1 0
- - - -
s s s s
where
b1 b0
-- --
0 0
0 1
Appendix E Communications Protocol
meaning
c band
k band