Value expressions, E value expressions – Delta RMC151 User Manual
Page 346
RMC70/150 and RMCTools User Manual
5.13.4. Value Expressions
A value expression evaluates to a number. Value expressions are used in the Delay Link Type,
in command parameters in user programs, and to programmatically select commanded axes in
user programs.
Value expressions can be very simple, for example just a tag name, such as
Axis[1].ActPos
.
Sample Expressions
Example 1
MyPosition + 10
Note: MyPosition must exist as a variable.
Example 2
_Axis[1].ActPrs
-
_Axis[0].ActPrs
Example 3
3.0 +
ABS
(
_Axis[].ActPos
);
Entering an Expression
Delay Link Type
1. In the Delay Link Type, double-click the Time to Delay box. The Expression Editor will
open.
2. Enter the expression:
•
Double-click any item in the lists on the Tags, Functions or Operators tabs
to insert into the expression.
•
Type other items, such as register addresses or numeric values.
•
To mix data types, you must explicitly convert them. For example, you cannot
directly assign a fractional value to an integer variable. You must use the data
type conversion functions.
•
If you enter multiple expressions in the Expression command, each expression
must end with a semi-colon. See the examples below.
•
If the expression is invalid, the Expression Builder give an error. When no
errors are listed, the expression is valid.
3. Click OK to close the dialog and enter the expression in the command.
Command Parameters
1. In a command parameter in a user program, double-click the box.
Notice that the Expression Editor is not available when entering expressions in
command parameters. it is good practice to only use short expressions in Command
Parameters. If you need a long expression in a command parameter, consider creating
a variable instead that is calculated in an expression command, and then entered in
the command parameter.
2. Enter the expression:
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