Aerotech UNIDEX 600 Series, User Manual

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U600 User’s Guide Programming
Version 1.4
Aerotech, Inc.
3-5
3.3. CNC G-code Programming
G-code motion consists of RS-274 compatible programs executed on the UNIDEX 600
Series controller. The user compiles, downloads, and starts these programs using library
interface calls, but the actual program execution is performed independent of the PC
processor. Therefore, program execution speed is totally independent of what programs
are running on the PC, the speed of the ISA bus, and the speed of the PC.
Another major advantage to CNC programming is, it uses the RS-274 standard, a industry
standard programming language accepted and understood in many manufacturing
environments. Furthermore, many third party applications exist that can translate CAD
data into RS-274 G-code programs.
A serious drawback of the CNC interface is it lacks the language sophistication of PC
languages like Visual C++ and Visual Basic. Most notably, the only GUI interface
capability available in the CNC language is the DISPLAY command, as opposed to the
full range of GUI capabilities in Visual C++ or Visual Basic. For this reason, CNC
language users usually use the U600 MMI to control their programs from a visual
environment, or they write their own library interface GUI application that controls the
CNC.
Although the CNC language is not as rich as C or C++, it should be mentioned here that
the AEROTECH U600 CNC language goes far beyond the RS-274 language in providing
language structures normally only found in languages such as C. Refer to the UNIDEX
600 CNC Programming Manual Win NT/95, P/N EDU 158 for more details.
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Block structures (if-endif, while-endwhile, etc.)
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Subroutines with parameters, returns and full stack capabilities
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Full access to all parameters and I/O (digital and analog)
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Full “define” capabilities, allowing for user-defined G-codes or M-codes.
In addition the AEROTECH CNC language offers a wide range of motion capabilities
beyond the RS-274 standard:
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Coordinate system rotation and mirroring (G83, G84)
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Asynchronous Motion (STRM)
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Up to sixteen spindles (S word)
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Simultaneous rotational and linear movement (G98, G99)
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Cutter Compensation (G40)
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Normalcy Motion (G20)
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PSO support (PSOC)
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Data Collection (DATACOLLECT)
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HandWheel Support (HAND)
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Analog and Digital Probe Support (PROBE)
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Disk file I/O (FILEOPEN)
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Continuous I/O monitoring (ON/ONGOSUB)
Unlike the library interface, modifications to the sequence and types of motion executed
can be made at any time by the user by modifying the G-code program and re-
downloading the file to the UNIDEX 600 controller (using the U600 MMI program).
Also, the end-user can stop and restart applications at will with the U600 MMI
application. This may or may not be an advantage depending on the particular
application.