Gemini GV6K and Gemini GT6K Programmer's Guide

Conditional Looping and Branching
Flow Control
Expression
Examples
Conditional looping (REPEAT/UNTIL and WHILE/NWHILE) entails repeating a set of
commands until or while a certain condition exists. In conditional branching
(IF/ELSE/NIF), a specific set of commands is executed based on a certain condition. Both
rely on the fulfillment of a conditional expression, a condition specified in the UNTIL,
WHILE, or IF commands.
A WAIT command pauses command execution until a specific condition exists.
This section provides examples of expressions that can be used in conditional branching and
looping commands (UNTIL, WHILE, and IF) and the WAIT command. These expressions can
be constructed, in conjunction with relational and logical operators, with the following
operands:
• Numeric variables and binary variables
• Inputs and outputs
• Current motion parameters and status
• Current commanded and actual position
• Error, axis, and system status
• Timer value
• Data read from the serial port
• Data read from the RP240
• Following conditions
• Multi-tasking conditions
Numeric and Binary
Variables
A numeric variable (VAR or VARI) can be used within an expression if it is compared against
another numeric variable, a value, or one of the comparison commands (see list on page 7).
When comparing a variable against another value, variable, or comparison command, the
relational operators (=, >, >=, =, =, , >=,