Variable Assembly Language

Variable Algorithmic Language (VAL) is a computer based control system and language designed specifically for use with 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 consist of easy to understand word and number sequences. Control programs are written on the same computer that controls the robot. As a 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. The VAL language consists of monitor commands and program instructions. The monitor commands are used to prepare the system for execution of user written programs. Program instructions provide the repertoire necessary to create VAL programs for controlling robot actions.

The following terms are frequently used in VAL related operations.

The VAL monitor is an administrative computer program that oversees operation of a system. It accepts user input and initiates the appropriate response; follows instructions from user written programs to direct the robot; and performs the computations necessary to control the robot.

The VAL editor is an aid for entering information into a computer system, and modifying existing text. It is used to enter and modify robot control programs. It has a list of instructions telling a computer how to do something. VAL programs are written by system users to describe tasks the robot is to perform.

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.

The standard VAL system uses an operator's console terminal and manual control box to input commands and data from the user. The operator console serves as the primary communication device and can be either a direct play terminal or a printing terminal. Interaction with other devices in an automated cell is typically handled by monitoring input channels and switching outputs. By this means the robot can control a modest cell without the need for other programmable devices.