Excellon Drill File - M70

I am reviewing PCB Gerber files returned to me by the PCB fab house 
after their edits.  I am not able to load the Excellon drill file oddly 
enough.  It has an M70 code which GerbV flags as an error.

When I look up the M70 code I can't find a definition for it other than 
in the rather wordy command, "M02X#Y#M70" which is called Swap Axis.   I 
do find M70 alone in many example files.  I see it under "Inch Measuring 
Mode M72".  So is M70 a synonym for M72?  Excellon seems to indicate M70 
is "format 1" while M72 is "format 2".

So how is M70 different from "INCH,LZ"?  The example on the following 
Excellon page has an example drill file with both commands.

http://www.excellon.com/manuals/program.htm

If this is valid, why doesn't GerbV accept it?

-- 

Rick

rickman wrote:

> I am reviewing PCB Gerber files returned to me by the PCB fab house
> after their edits.  I am not able to load the Excellon drill file oddly
> enough.  It has an M70 code which GerbV flags as an error.
> 
> When I look up the M70 code I can't find a definition for it other than
> in the rather wordy command, "M02X#Y#M70" which is called Swap Axis.

Wow, never heard of this command.  I have the "Gerber format guide" 
published by Gerber Systems Corp in 1994, and I can't find any mention of 
the M70, they only list up to M65.

If it really is a swap axes command, you can just comment it out, and it 
should display it as you originally drew it.  The swap axes might be for 
their own manufacturing convenience to fit the multi-up boards to their 
standard panels.

Jon

On 8/7/2015 12:50 AM, Jon Elson wrote:
> rickman wrote:
>
>> I am reviewing PCB Gerber files returned to me by the PCB fab house
>> after their edits.  I am not able to load the Excellon drill file oddly
>> enough.  It has an M70 code which GerbV flags as an error.
>>
>> When I look up the M70 code I can't find a definition for it other than
>> in the rather wordy command, "M02X#Y#M70" which is called Swap Axis.
>
> Wow, never heard of this command.  I have the "Gerber format guide"
> published by Gerber Systems Corp in 1994, and I can't find any mention of
> the M70, they only list up to M65.
>
> If it really is a swap axes command, you can just comment it out, and it
> should display it as you originally drew it.  The swap axes might be for
> their own manufacturing convenience to fit the multi-up boards to their
> standard panels.

The issue is that I am verifying the changes made by the PCB house where 
they clipped the silkscreen file around the vias.  They had been 
clipping around the via pads and now they are clipping around the via 
holes only.

I don't think they are using it as "swap axis" because the rest of the 
command is not there, just the M70 code.  I did find where the M70 
command also invokes the "Inch Measuring Mode - M72".  I'm not very 
clear on the whole "Format 1, Format 2" thing, but it seems they created 
a second generation of machines which used a format slightly 
incompatible with the first.  So M72 is a command in format 2, while the 
same command is M70 in format 1.

The question still remains, why does Gerbv not recognize this command? 
Or maybe I should be asking the question, why does the PCB maker's 
software use this command rather than a format 2 command?  Old software 
I suppose.

BTW, dinking with the "reply to" in your post makes replying to them a 
pita.

-- 

Rick

On 8/7/2015 5:25 PM, Jon Elson wrote:
> rickman wrote:
>
>
>> BTW, dinking with the "reply to" in your post makes replying to them a
>> pita.
> Why?  My reply to: is the same as my from:  (at least when I'm sending from
> home.)  I had to do this crap to satisfy overly picky ISPs when traveling.

The two messages I replied to had "Choose, an, appropriate,..." in the 
"Followup to" field, as did this one.  That generates many invalid 
newsgroup entries in my reply *each* of which have to be deleted before 
I can enter a valid newsgroup.  How is that useful to anyone?


> As for the G70, if you take it out, it OUGHT to render the drill file with
> whatever changes they made.  You then talk about the silkscreen, that would
> be in the Gerber files, not the drill file.

Uh, the command is "M70".  Yes, I can figure out to remove this from the 
file, but then I am *not* verifying the file I was sent, am I?

The issue is the silk screen layers wrt the drill holes and via pads. 
So I need all five layers working properly so I can see how much overlap 
there is with the via holes and via pads.

I'm not asking anyone to rethink this issue for me.  I'm asking if 
anyone has knowledge of this problem so I can know what to expect from a 
Gerber viewing program.  The info on the Excellon drill file format is 
not as clear as I would like.  How Format 1 and Format 2 are 
distinguished is not at all clear.

-- 

Rick

On 08/08/2015 06:28, rickman wrote:
> On 8/7/2015 5:25 PM, Jon Elson wrote:
>> rickman wrote:
>>
>>
>>> BTW, dinking with the "reply to" in your post makes replying to them a
>>> pita.
>> Why?  My reply to: is the same as my from:  (at least when I'm sending
>> from
>> home.)  I had to do this crap to satisfy overly picky ISPs when
>> traveling.
>
> The two messages I replied to had "Choose, an, appropriate,..." in the
> "Followup to" field, as did this one.  That generates many invalid
> newsgroup entries in my reply *each* of which have to be deleted before
> I can enter a valid newsgroup.  How is that useful to anyone?
>
>
>> As for the G70, if you take it out, it OUGHT to render the drill file
>> with
>> whatever changes they made.  You then talk about the silkscreen, that
>> would
>> be in the Gerber files, not the drill file.
>
> Uh, the command is "M70".  Yes, I can figure out to remove this from the
> file, but then I am *not* verifying the file I was sent, am I?
>
> The issue is the silk screen layers wrt the drill holes and via pads. So
> I need all five layers working properly so I can see how much overlap
> there is with the via holes and via pads.
>
> I'm not asking anyone to rethink this issue for me.  I'm asking if
> anyone has knowledge of this problem so I can know what to expect from a
> Gerber viewing program.  The info on the Excellon drill file format is
> not as clear as I would like.  How Format 1 and Format 2 are
> distinguished is not at all clear.
>
The M70 is just an X,Y origin command. Take it out and move on with what 
you want to do.

---
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