Finding program-related parameters
In this issue’s G Code Primer, we discuss how to program certain program-related parameter changes with G10. Doing so, of course, requires that you know the parameter numbers related to the function the parameter controls. This is true regardless of whether you with to program the parameter change of manually modify the parameter. In either case, you’ve got to know the parameter number for the function in question.
Parameters can be difficult to locate. And parameter numbers vary from one control model to another, meaning even if you know the related parameter number for one control, you will still need to find if for another.
One way to find parameters is to look in the parameter documentation and begin searching at parameter number zero. While I’d recommend doing this just to see the various parameters related to a given control – and what it’s possible to change – it doesn’t make a very efficient method of finding a given parameter (the image of a needle in a haystack comes to mind).
With newer controls,parameters are organized into categories, which considerably narrows the search. But it can still be difficult (based on the parameter’s documentation) to determine if the parameter you’ve found is truly the one in question. Additionally, there are several parameters that have not been properly categorizes – especially those from number zero to about number one-hundred.
The best place to start looking for a needed parameter is in the documentation that describes the feature dealt with by the parameter. This documentation is in the programming portion of the control manufacturer’s manual/s.
If you’re trying to find the parameter number for the parameter that controls the final pass depth for threading, look in the programming manual at the section that describes G76. If you’re looking for the parameter number for the parameter that controls the retract amount for the chip-breaking peck-drilling cycle, look in the section that describes G73. If you’re trying to find a parameter that is related to custom macro B, look in the custom macro B section of the programming manual.
Somewhere in the description of each programming function – and usually in a series of notes at the end of the function’s description, you’ll find documentation about each parameter that is related to the programming function.