Re: [CAD_CAM_EDM_DRO] RS274 vs RS274-NIST

Carol & Jerry Jankura wrote:

> Guys,
>
> I've started reading through the NIST release 3 publication, one chapter of
> which describes the operation of the various G-Codes that the NIST system
> supports. It appears that the NIST version supports some codes that my
> controller does not and does not support others that it does. For example,
> NIST uses G83 for "peck" drilling while the controller I'm working wirh,
> TurboCNC uses G78 for what appears to be the same function.
>
> Now, I do understand that there are several "standards" that masquerade as
> RS274. Is the NIST G83 code the same as the TurboCNC G78 code, or are there
> some subtle differences between the two? Are there any other "equivalent"
> codes that port from one machine to another. Would I get the "correct" peck
> drilling cycle if I assigned the G-Code G83 to the same procedure that
> TurboCNC uses for G78? Does any table that lists all of the known G-Codes
> exist? If so, where?

Canned cycles are totally machine specific, and historically, could be ordered

differently for each machine. Nobody expects these to be the same across
different controls.

G83 is standard peck deep hole drilling cycle for Allen Bradley controls,
whose dialect was used as a model for EMC.

In the official RS-274D spec issued by the EIA in 1980, G76 - G79 are
unassigned. G83 is assigned as "fixed Cycle No. 3", clearly indicating that
the control manufacturer could do what he pleased with this code. G81 -G89
are the canned cycle codes.

There really can't be a table of all known G-codes, because the canned cycles
are so machine dependent. (They are a lot more standardized, now, than they
were
in the 1970's. Literally, then, you could have 2 machines with consecutive
serial numbers sitting side by side, that had different canned cycles!)

Jon