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567 
Software for the computer-controlled Rectimat C rectifier 
Dipl.Yath. Horst Zahn- 
VEB Carl Zeiss JENA 
GDR 
Commission II/3 
In photogrammetric instrumentation digital techniques become 
more and more important. Their applications range from tasks of 
data acquisition to the control and realization of internal 
instrument functions. This also applies to the field of rectifiers. 
The Rectimat C precision rectifier is an equipment of the new 
generation featuring a very high optical efficiency, a precise 
mechanical construction as a prerequisite for high accuracy and 
an efficient electronic system including microcomputer with the 
appertaining software. The programs which in their entirety are 
termed software have to ensure the operation of the equipment and 
to control the functional processes. 
The software consists of the computer, control and operating 
software. 
The computer software includes 
- ihe counter programs which ensure the taking over of the count 
values and the counting of the. setting values for the supplemen- 
tation of the 8-bit hardware counters as well as the availability 
of the current values of the Setting elements; 
- the model calculation programs for the mathematical model, which 
realize the formulas of the Scheimpflug and Newton conditions 
and in which simultaneously correction calculations are carried 
out for the individual setting elements (correction of residual 
errors of the axial system and the like). 
This software also includes an arithmetic fixed-point program 
package. 
The control software comprises programs for 
the positioning of the setting elements in the zero position, 
the motion of the independent setting elements Bln Da ox ey, 
the regulation of the motor speed (start-up, braking), 
the positioning of the setting elements to preselected values. 
The operating software includes 
button identification programs, 
- processing of button information (multiply used buttons, different 
phases of operation etc.), 
- control of lamps allocated to the buttons, 
- Setting of the filter and diaphragm system as well as of the 
projection lamp (position blue, green, red) and the tilt 
compensation filter, ] 
- operation of the shutter, 
- display programs for the various equipment states (including 
converting programs) and darkening of the display, 
- error recognition routines and error signalization.