Aux Positioner Lecture Notes

the Annex .
The description of the controller message codes of and errors are presented in
At measurements in the scanning mode with measuring equipment starting di-
rectly from control system the "START" signals are formed on the controller plate by
special former controlled by the controller processor. Duration of a pulse is soft defined
and is equal to 7 mcs. Polarity of pulses is positive.
4.2 The arithmetic-logic unit.
Arithmetic-logic unit (ALU) is intended for the calculation of 16-digit binary code
(in view of a sign) of a difference between the task for movement and the value of a
code of the feedback transducer. The code of the transducer is read out from PCT. The
received code of the difference for each coordinate (azimuth or elevation) is sent to the
power amplifiers, which are carrying out drives control.
ALU has two operating modes:
- Automatic control;
-Manual control.
ln automatic operating mode ALU calculates the difference for each of coordi-
nates by multiplexing in time of the moments of the information processing, which are
determined by the control signals former. The task for movement and movement control
(Start / stop) by each coordinate is carried out by the HPIB controller (CHPIB) according
to the commands received from the control computer and algorithms of the control sys-
tem functioning.
In a manual operating mode each coordinate control is carried out by means of
the controls located on the ALU front panel, or on the manual control unit (MCU). Basic
electric schematic diagram of ALU is presented in the Annex 2-2. Basic electric sche-
matic diagram of MCU is presented in the Annex 2-6.
Functionally ALU of the auxiliary positioner control system corresponds to the
ALU of PP-1 and PP-z.
The positioner control in a manual operating mode is carried out with the help of
the ALU front panel. The schematic diagram of the front panel is presented in the An-
nex .
ALU front panel is a microprocessor controller realized on microcircuit AT89C52
what is different from ALU of PP-1 and PP-2. Buttons START and STOP. the switch of
operating modes, buttons of the coordinates and speeds task setting, and the toggle-
switch of inclusion MCU are connected to the microprocessor. To display the value of
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