Tormach PCNC 440 - 7.6.3 Change Tool Number - T; 7.7 Advanced Programming with Parameters and Expressions; 7.7.1 Parameters

Chapter 7
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UM10372_PCNC440_Manual_0221A
PROgRAMMiNg
7.6.3 Change Tool Number – T
It is the programmer’s responsibility to ensure that the carriage is in a safe place for changing tools,
for example by using G30. This allows opmizaon of moon which can save me, especially with
gang tooling. A pause for manual intervenon can always be provided by an M00 or M01 before the
tool change. It is an error if:
• A negave T number is used or a T number larger than 54 is used
7.7 Advanced Programming with Parameters and Expressions
This secon describes the parameter and expression programming language features of PathPilot.
You may wish to skip this secon on rst reading as these features are not used in common G-code
applicaon (hand coding), G-code created by the PathPilot conversaonal programming interface,
or the majority of third-party CAM-programming systems.
NOTE: There are signicant dierences between controls in the way parameters work. Do not assume that
code from another control works in the same way with the operang system. Tormach advises against
wring parametric G-code as this is dicult to debug and very dicult for another operator to understand.
Modern CAM virtually eliminates the need for it.
7.7.1 Parameters
The RS274/NGC language supports parameters. Parameters are analogous to variables in other
programming languages. PathPilot maintains an array of 10,320 numerical parameters. Many of
them have specic uses. The parameters that are associated with xtures are persistent over me.
Other parameters are undened when the operang system is loaded. The parameters are preserved
when the interpreter is reset. Parameters 1 to 1000 can be used by the code of part-programs.
There are several types of parameters of dierent purpose and appearance. The only value type
supported by parameters is oang-point; there are no string, Boolean or integer types in G-code
like in other programming languages. However, logic expressions can be formulated with Boolean
operators (AND, OR, XOR, and the comparison operators EQ, NE, GT, GE ,LT, LE), and the MOD,
ROUND, FUP and FIX operators support integer arithmec.
Parameter Syntax
There are three types of parameters, numbered, named local, and named global. The type of the
parameter is dened by its syntax:
numbered - #4711
named local - #<localvalue>
named global - #<_globalvalue>