Kipp&Zonen 2AP Sun Tracker - Manual (Page 88)

REFERENCE INFORMATION
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XTent
Sets the travel range of the instrument. Returns XT. This range must be set in accordance with the
actual hardware and must be specified in revolutions (e.g. xt 1 -0.273 0.0138 for a range of 97.5
deg to 5 deg). This command is only permitted after protection has been removed with the PWord
command.
6.2.2 Operation Commands
The 2AP carries out movements as a series of cubic functions of position over time. A series of
cubic functions is referred to as a path. A path consists of one or more path segments. Each
segment consists of a cubic function of position against time and a duration for which that function
should apply. The 2AP maintains a queue of path segments for each motor, allowing a controller to
send a complex series of movements to the 2AP and then ignore the 2AP while the movements are
carried out.
The 2AP calculates path segments as movement commands are received and adds the segments
to the queues. All commands except ADjust and CLear and their derivatives (e.g. HOme), take
effect after all previously queued movements have completed. If a motor runs out of path segments
to perform, that motor will decelerate and stop (if it was not already stopped). The 2AP keeps track
of the position and velocity that each motor will have when all queued path segments are
completed.
The CLear, HOme, POsition and MOve commands generate a complete path internally. All
paths generated on the 2AP will stay within the bounds of the operating configuration and cause no
step changes in velocity.
The 2AP is idle when all motors are stopped and no motors have any path segments in their
queues.
Angular values are positive for a clockwise (as seen from above for azimuth and as seen from
azimuth+90° for zenith) sense to the motion or position and are negative for a counter-clockwise
sense.
ADjust
Retrieve the tracking adjustment for all motors. Returns AD 1>. Adjustments are reported in degrees.
ADjust
Cause the physical position to be further clockwise while the
logical position remains the same. The sum of all adjustments is called the total adjustment. The
parameter must be within acceptable limits (-0.21° and +0.21°) and must
not cause the total adjustment to exceed 4°. This command is only permitted after protection has
been removed with the PWord command.
CHeckout
Applies to all motors. Adds a path segment or segments to each path so that once the motor
reaches the end of its specified path, it returns to the reference point and remains there until the
real time clock reaches the indicated value.
This has the effect of synchronizing the CPU clock used to drive motion to the accurately
maintained real time clock. Returns CH. If the reference position is found at some point other than
where it is expected (that is if the motor position has somehow slipped) the motor position is
realigned. Once this command is completed, the adjustment has been set to 0. This command is
only permitted after protection has been removed with the PWord command.