Yaskawa LEGEND-MC - Manual (Page 291)

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LEGEND-MC User’s Manual
7 Application Programming
Introduction
The LEGEND-MC programming language is a powerful language that allows users to customize a
program to handle their application. Complex programs can be downloaded into the LEGEND-MC
memory for later execution. Utilizing the LEGEND-MC to execute sophisticated programs frees the host
computer for other tasks. The host computer can still send commands to the controller any time, even
while a program is being executed.
In addition to standard motion commands, the LEGEND-MC provides commands that allow the
LEGEND-MC to make its own decisions. These commands include conditional jumps, event triggers,
and subroutines. For example, the command JP#LOOP, N<10 causes a jump to the label #LOOP if the
variable N is less than 10.
For flexibility, the LEGEND-MC provides 254 user-defined variables, arrays and arithmetic functions,
i.e.; length in a cut-to-length operation can be specified as a variable in a program and assigned by an
operator.
The following sections in this chapter discuss all aspects of creating applications programs.
Program Format
A LEGEND-MC program consists of several LEGEND-MC instructions combined to solve a machine
control application. Action instructions, such as starting and stopping motion, are combined with
Program Flow instructions to form the complete program. Program Flow instructions evaluate real-time
conditions, such as elapsed time or motion complete, and alter program flow accordingly.
A delimiter must separate each LEGEND-MC instruction in a program. Valid delimiters are the
semicolon (;) or carriage return. The semicolon is used to separate multiple instructions on a single
program line. A carriage return enters the final command on a program line.
All LEGEND-MC programs must begin with a label and end with an End (EN) statement. Labels start
with the pound (#) sign followed by a maximum of seven characters. The first character must be a letter;
after that, numbers are permitted. Spaces are not permitted.
The maximum number of labels that may be defined is 126.
Valid labels
#BEGIN
#SQUARE
#X1
#BEGIN1
Invalid labels
#1Square
#123