Variable Assembly Language: Difference between revisions

Revision as of 19:44, 14 June 2007

Revision as of 20:41, 2 July 2008

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VAL is a [[computer]]-based [[control system]] and language designed specifically for use with [[Unimation|Unimation Inc.]] industrial robots.

The VAL [[robot]] language is permanently stored as a part of the VAL system. This includes the programming language used to direct the system for individual applications. The VAL language has an easy to understand syntax. It uses a clear, concise, and generally self-explanatory [[instruction set]]. All commands and communications with the robot compriseconsist of easy to understand word and number sequences. Control programs are written on the same computer that controls the robot. As a [[real-time computing|real-time]] system, VAL's continuous [[trajectory]] computation permits complex motions to be executed quickly, with efficient use of system memory and reduction in overall system complexity. The VAL system continuously generates robot control commands, and can simultaneously interact with a human operator, permitting on-line program generation and modification.

A convenient feature or VAL is the ability to use libraries or manipulation routines. Thus, complex operations may be easily and quickly programmed by combining predefined subtasks.

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object. Locations are used to define the positions and orientations the robot tool is to assume during program execution.

==VAL Programmingprogramming==

Several conventions apply to numerical values to be supplied to VAL commands and instructions. Preceding each monitor-command description are two symbols indicating when the command can be typed by the user. A dot (.) signifies the command can be performed when VAL is in its top-level monitor mode and no user program being executed (that is, when the system prompt is a dot). An asterisk (*) indicates the command can be performed at the same time VAL is executing the program (that is, when the system prompt is an asterisk). If both symbols are present the command can be executed in either case. Most monitor commands and program instructions can be abbreviated. When entering any monitor command or program instruction, the function name can be abbreviated to as many characters as are necessary to make the name unique.

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Many VAL commands and instructions have optional arguments. For notations, optional arguments are enclosed in square brackets, [ ]. If there is a comma following such an argument, the comma must be retained if the argument is omitted, unless nothing follows. For example, the monitor BASE command has the form:

BASE [<dx>] , [<dy>] , [<dz>] , [<rotation>]

To specify only a 300-millimeter change in the Z direction, the command

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nearest representable value.

==The VAL Systemsystem==

The function of VAL is to regulate and control a robot system by following user commands or instructions. In addition to being a compact stand-alone system, VAL has been designed to be highly interactive to minimize programing time, and to provide as many programming aids as possible.