[Al_The_Man]

I guess I am one of those with the opposite view as why you should need or have to modify G codes, as I believe that G codes are not machine specific only as far as to what type of machine i.e. Mill, Lathe, EDM etc. and that a package together with the appropriate G codes should be supplied by the System supplier.
I think you will find this issue of standard G codes drawn accross two lines, those that are DIY'ers and hobbyists and the retrofitters that make a living at it.
If I install a Fanuc or Mitsubishi system I do not have to, or expect to tinker with the G code part of the installation. And the fact that both of these systems are complete down to the amps and motors makes no difference.
Fanuc or Mitsubishi do not know any details of the machine or system (only type) I am installing on. As long as I carry out my side of the installation correctly, sizing motors and tuning etc. Then I expect the neccessary G code to perform as outlined in the RS-274 standard.
For example if I retrofit a Lathe and I want to use G84 threading option. If I have the required hardware in place I have never come across any frustration in wanting to get into the G code to change anything.
The point of having to modify the G01 command is an example of what I mean. The G01 F command is usually modal, so once I have issued it I do not have to specify it again unless I want to change it.
Fanuc & Mitsubishi and others will give me a warning alarm if I have not issued an F command greater than zero at first G01 .
For several years Fanuc & Mitsubishi (Mazak) sold 85 to 90% of the CNC market so the standards have evolved through them to a certain extent and for better or worst, most of the major followers have followed their lead.
I always hear cries about ladder logic, Ladder is based on the diagramatic display of what was once the wiring schematic for a machine in order for maintenance personell to become familiar with what they already knew, unfortunately the functions and commands became much more than the average electrician could follow or was familiar with.
All ladder is, is a diagramatic form of booleian** logic which has been around for years. And is a form of mathematics that is used to express functions in electronic circuitry.
As hillbilly mention, the ladder display is very usefull when diagnosing a machine fault to find out what piece of logic is causing the problem.
I have programmed with Fanuc Ladder and Mitsubishi and many other PLC's and most give you the option of ladder or Boolean and will convert one to the other and I am no math whizz by any means but do not find this any more difficult than the logic used by Camsoft et.al.
There is a learning curve to any thing worthwhile.
We beg to differ.
AL.
**George Boole, english mathematican, died 1864, invented Boolean arithmetic, unfortunately there was no use for it in his lifetime, computers came along later and the rest is history.