Calian SatService sat-nms ACU-19V, User Manual

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7.5 One line read via TCP/IP
For compatibility with the sat-nms power sensor, the ACU also may be polled for an automated
monitoring by the requesting the 'position' document with a HTTP GET command. Assuming the
ACU listens to the IP address 10.0.0.1, the complete URL for the request is:
http://10.0.0.1/point?fmt=txt
The 'fmt=txt' parameter forces the power sensor to reply a one line text document rather than the
HTML coded page which is normally displayed by the web browser.
The ACU answers a 'text/plain' type document which consists of one line. As shown in the example
below, the line consists of a set of keyword - value pairs, separated by '&' characters. Within each
pair, keyword and value are separated by the '=' character.
apos=174.688&epos=31.456&ppos=-34.5&atar=174.700&etar=31.500&ptar=-34.5&blev=-
64.33&temp=63.5&obit=FFFF0000&ibit=FFFF0000&
The format does not use fixed column widths for the values, however the precision of floating
point values is always as shown in the example. An application which parses this string should not
rely on the order of the values in the line. Future version of the ACU may provide additional
values which not necessarily will appear at the end of the line. A description of the parameters is
given in the chapter
Parameter list above.
8 Theory of Operation
This section gives some background information about how the ACU works.
Chapter 8.1 Angle Measurement describes how the ACU measures the antenna pointing and how
it calculates the angles displayed at the user interface.
Chapter 8.2 Pointing / Motor Control describes the way the ACU performs the antenna pointing
and how it controls the motors.
Chapter 8.3 Steptrack describes the step track method used by sat-nms ACUs providing this
function.
Chapter 8.4 Adaptive Tracking describes the adaptive (orbit prediction) tracking method used by
sat-nms ACUs providing this function.
Chapter 8.5 Program Tracking describes the program / file tracking capability built into the sat-
nms ACU.
8.1 Angle Measurement
The sat-nms ACU provides exchangeable interfaces for several types of position sensors.
Position sensor interfaces may be selected individually for each axis. This gives a maximum of
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