I need a usb3 to rs232 adapter that WORKS RIGHT

On 8/17/19 4:31 AM, Carlos E.R. wrote:
On 16/08/2019 18.52, Mark Lloyd wrote:
On 8/15/19 12:58 PM, Paul wrote:

[snip]

So it's parallel, four bits at a time, with two signals mixed
on the cable at the same time.

4-bit parallel, or 4-lane serial (like PCIe x4)?

That's serial in my book. Parallel is 8 wires. One word per bus clock
cycle, one pin per bit.

Older printers used 7 bits. Parallel is multiple wires, with a common
clock. Number doesn't change anything. IIRC, some versions of SCSI used
16-bit parallel.

But my book did not consider these, so I would say multilane serial.



--
Mark Lloyd
http://notstupid.us/

"Irreligion: The principal one of the great faiths of the world." --
Ambrose Bierce

On 17/08/2019 19.46, Mark Lloyd wrote:
On 8/17/19 4:31 AM, Carlos E.R. wrote:
On 16/08/2019 18.52, Mark Lloyd wrote:
On 8/15/19 12:58 PM, Paul wrote:

[snip]

So it's parallel, four bits at a time, with two signals mixed
on the cable at the same time.

4-bit parallel, or 4-lane serial (like PCIe x4)?

That's serial in my book. Parallel is 8 wires. One word per bus clock
cycle, one pin per bit.

Older printers used 7 bits.

Except that I never saw them, because in Spain you need 8 bit to handle
letters like 'ñ' or the accented wovels. Maybe not never, but rarely,
and they printed garbage when the 'ñ' came by. Similar problem in the
rest of Europe except Britain.

Parallel is multiple wires, with a common
clock. Number doesn't change anything. IIRC, some versions of SCSI used
16-bit parallel.

Sure. just whatever is the machine definition of word. or another word
for "word" :-)


But my book did not consider these, so I would say multilane serial.



--
Cheers, Carlos.

On 8/16/19 8:55 PM, Paul wrote:
T wrote:

And no power pins I can see on a DB25 conenctor:

https://opengear.zendesk.com/hc/en-u...nnector-pinout


They must be using a gimmick as you say.


An example of the scheme is in the epanorama article.
Diodes are used to provide a one way path to charge
a cap, and which ever status pin is driving the
desired potential at the time, charges the cap.
Only a few milliamps can be "harvested" that way.

http://www.epanorama.net/circuits/rspower.html

*******

As for why there isn't power on the connector,
part of it was probably a lack of imagination.

Also, being cost focused, they want to keep the
connector design as cheap as possible (pressed
metal pins, not milled). And even though the
design is pretty cheap, the retail price of the
connectors isn't all that impressive. Imagine
what it would have cost to put recessed or
advanced power pins on the serial port connector.

*******

If computers had the VGA connector designed
properly, it would have looked like this.
The RGB pins are RF quality. You could drive
a higher resolution signal, without reflections
or ghosting. That's the idea behind these, even
though the res never got all that high where
these were involved.

https://en.wikipedia.org/wiki/DB13W3

And some companies did do crazy things for power.
Apple put +25V or so on their monitor cable, so
the monitor would not need its own AC cord, and
could get the desired power directly from the
computer chassis. It's a great mechanism for lock-in.

Â*Â* Paul

Sort of like the way a switching power supply works.

Carlos E.R. wrote:
On 17/08/2019 19.46, Mark Lloyd wrote:
[...]
Parallel is multiple wires, with a common
clock. Number doesn't change anything. IIRC, some versions of SCSI used
16-bit parallel.

Sure. just whatever is the machine definition of word. or another word
for "word" :-)

A word is 16 bits! [1] Any other 'words' are Fake Words! :-)

[1] My computing career started with the HP 2116A, a 16-bit computer.
http://www.hpmuseum.net/display_item.php?hw=95

On 8/22/19 2:30 PM, Frank Slootweg wrote:
Carlos E.R. wrote:
On 17/08/2019 19.46, Mark Lloyd wrote:
[...]
Parallel is multiple wires, with a common
clock. Number doesn't change anything. IIRC, some versions of SCSI used
16-bit parallel.

Sure. just whatever is the machine definition of word. or another word
for "word" :-)

A word is 16 bits! [1] Any other 'words' are Fake Words! :-)

[1] My computing career started with the HP 2116A, a 16-bit computer.
http://www.hpmuseum.net/display_item.php?hw=95

That (16 bits) does seem to be the usual definition of "word".

The first I heard, was a word being the bitsize of a particular device
(as in, the 6502 CPU has an 8-bit word).

--
Mark Lloyd
http://notstupid.us/

"It is possible that mankind is on the threshold of a golden age; but,
if so, it will be necessary first to slay the dragon that guards the
door, and this dragon is religion." [Bertrand Russell]

On 8/16/19 7:57 PM, Andy Burns wrote:
Paul wrote:

If you're Googling, you state that as "8N1".
If I search on 7N2,

The only time (in the late 80s) I ever had to use 7N2, was when a
mainframe was sending 7E1 but the local equipment connected via a mux
had no option to ignore parity errors, so setting it for 7N2 let it
"eat" the parity bit as an extra stop bit ... a kludge but it worked
when nothing else did.


The guy as getting unprintable characters on 7N2, but do
to privacy issues, I could not take a snapshot to hexedit it
and see what he was actually receiving.

One of his complains besides two empty line per line,
was that a "0" at the start of the line came out as
a ":". Zero's not at the start were fine.

There is way more going on here than what it looks like.
I think his CNC machine's interface (no manual) may have
gone foo bar

In article , wrote:


The guy as getting unprintable characters on 7N2, but do
to privacy issues, I could not take a snapshot to hexedit it
and see what he was actually receiving.

try 81n, or better yet, stop guessing and find out what it expects.

One of his complains besides two empty line per line,
was that a "0" at the start of the line came out as
a ":". Zero's not at the start were fine.

There is way more going on here than what it looks like.
I think his CNC machine's interface (no manual) may have
gone foo bar

presumably the cnc machine has worked in the past.

find out what the relevant settings were and use those.

T wrote:
On 8/16/19 7:57 PM, Andy Burns wrote:
Paul wrote:

If you're Googling, you state that as "8N1".
If I search on 7N2,

The only time (in the late 80s) I ever had to use 7N2, was when a
mainframe was sending 7E1 but the local equipment connected via a mux
had no option to ignore parity errors, so setting it for 7N2 let it
"eat" the parity bit as an extra stop bit ... a kludge but it worked
when nothing else did.


The guy as getting unprintable characters on 7N2, but do
to privacy issues, I could not take a snapshot to hexedit it
and see what he was actually receiving.

One of his complains besides two empty line per line,
was that a "0" at the start of the line came out as
a ":". Zero's not at the start were fine.

There is way more going on here than what it looks like.
I think his CNC machine's interface (no manual) may have
gone foo bar


0 (zero) is 0x30 hex
: (colon) is 0x3a hex

I don't immediately see a pattern there.

*******

They send a "U" which is hex 0x55 to train autobaud
in this hardware example. If the CNC machine is
cursed with autobaud, that's a variable right there.

https://www.microchip.com/forums/m917016.aspx

If the baud rate is fixed on the CNC, then things
should work.

If the CNC machine is really old, the baud rate
generator might not be very accurate at high baud
rates. In the old days, you might select 57600,
but the frequency error on the baud rate generator
was large enough, you couldn't communicate with
a 57600 connection from a different chip type.
The clocks have to be within tolerance close
enough, for a "burst of bits" to be received
correctly. Since the 16X sampling clock "restarts"
the synchronization process on each character, the
tolerance is not cumulative. The bits cannot be
squeezed or stretched too much, which would cause
the last bit in the stream to be mis-sampled.

"Determining Clock Accuracy Requirements for UART Communications"

https://www.maximintegrated.com/en/a...ex.mvp/id/2141

You can see in the picture there, you could eight
cycles after detecting "falling START", and that
defines where you'll be slicing all subsequent
bits (hopefully, in the center of each bit).

But that would be a problem with older equipment,
being asked to run higher than the typical
4800 or 9600 that some of the computers back
then could properly handle.

The baud rate generator in your USB dongle, is likely
to be much more sophisticated than the method used
on the CNC motherboard. The USB dongle can have
accurate clocks (by synthesis, if necessary),
while the CNC uses the "awful" method and
the high baud rates have significant percentage
frequency error.

*******

You could also test this in your "home lab".

Get a year 2000 machine and set up Hyperterm.
Select a baud rate, using the usual COM line
in Command Prompt.

Set up your dongle equipped test laptop and
cat some samples over your 7N2 link.

Have your customer make a "non-government design"
and use that to give you a G code file to play with.
Even a G code file to reset the machine and disable
the various modes, might be good enough for serial
link testing.

The article I could find on G codes, makes no mention
of CRC or checksums per record. Back in the day, we
were using S-records, and those were protected by a
checksum on the end. The protocol would then
"request a retransmit" starting at a certain address,
and thus, an occasional transmission error might be
detected and corrected (by retransmission). Today,
you could protect an entire transmitted file with SHA256
at the end of transmission, and be reasonably assured
the file was completely received. But the CNC machine
is not likely to be that sophisticated.

*******

If the customer is editing the CNC files with
Wordpad or Notepad, recent versions of Windows 10
can be adding three hex characters to the beginning
of the file. Unlike older versions of Windows which
did not. If you're ever having problems with text
files, by all means, pop the file into HxD and
have a look for a BOM.

Here's a guy using BOM a lot, in a sentence :-)

https://devblogs.microsoft.com/oldne...17-00/?p=27223

And that's really the essence of buying a new computer.
"They **** with *everything*..." :-( How bad is it,
when you can't trust text files any more ?

The text file that comes out of the CAM software
is probably OK. Just don't be editing, snipping,
and saving out, then transmitting to the CNC.
Or you just might find a BOM in the first three
characters while using HxD.

Paul

On 8/23/19 11:07 PM, Paul wrote:
0Â*(zero)Â*Â*isÂ*0x30Â*hex
:Â*(colon)Â*isÂ*0x3aÂ*hex

IÂ*don'tÂ*immediatelyÂ*seeÂ*aÂ*patternÂ*there.

Me either. I think something got buggered up on
his CNC machine. The same symptom occurred on two
different USB to RS232 adapters with different chip
sets.

This is driving me nuts. I wish he'd call me
back in so I can kick its ass!

On 23/08/2019 18.45, Mark Lloyd wrote:
On 8/22/19 2:30 PM, Frank Slootweg wrote:
Carlos E.R. wrote:
On 17/08/2019 19.46, Mark Lloyd wrote:
[...]
Parallel is multiple wires, with a common
clock. Number doesn't change anything. IIRC, some versions of SCSI used
16-bit parallel.

Sure. just whatever is the machine definition of word. or another word
for "word" :-)

Â*Â* A word is 16 bits! [1] Any other 'words' are Fake Words! :-)

[1] My computing career started with the HP 2116A, a 16-bit computer.
http://www.hpmuseum.net/display_item.php?hw=95

That (16 bits) does seem to be the usual definition of "word".

The first I heard, was a word being the bitsize of a particular device
(as in, the 6502 CPU has an 8-bit word).


Right. And the parallel printer port of PCs was 8 bit.

--
Cheers, Carlos.

On 24/08/2019 08.07, Paul wrote:
T wrote:
On 8/16/19 7:57 PM, Andy Burns wrote:
Paul wrote:

If you're Googling, you state that as "8N1".
If I search on 7N2,

The only time (in the late 80s) I ever had to use 7N2, was when a
mainframe was sending 7E1 but the local equipment connected via a mux
had no option to ignore parity errors, so setting it for 7N2 let it
"eat" the parity bit as an extra stop bit ... a kludge but it worked
when nothing else did.


The guy as getting unprintable characters on 7N2, but do
to privacy issues, I could not take a snapshot to hexedit it
and see what he was actually receiving.

One of his complains besides two empty line per line,
was that a "0" at the start of the line came out as
a ":".Â* Zero's not at the start were fine.

There is way more going on here than what it looks like.
I think his CNC machine's interface (no manual) may have
gone foo bar


0 (zero)Â* is 0x30 hex
: (colon) is 0x3a hex

I don't immediately see a pattern there.

0 0110000
: 0111010

O 4F 1001111
o 6F 1101111


*******

They send a "U" which is hex 0x55 to train autobaud
in this hardware example. If the CNC machine is
cursed with autobaud, that's a variable right there.

https://www.microchip.com/forums/m917016.aspx

If the baud rate is fixed on the CNC, then things
should work.

If the CNC machine is really old, the baud rate
generator might not be very accurate at high baud
rates. In the old days, you might select 57600,
but the frequency error on the baud rate generator
was large enough, you couldn't communicate with
a 57600 connection from a different chip type.
The clocks have to be within tolerance close
enough, for a "burst of bits" to be received
correctly.

We used RC oscillators as clocks :-)
Which is why there were stop and start bits in the RS232 protocol, they
restarted the clock on each byte.

Since the 16X sampling clock "restarts"
the synchronization process on each character, the
tolerance is not cumulative. The bits cannot be
squeezed or stretched too much, which would cause
the last bit in the stream to be mis-sampled.

Right.


"Determining Clock Accuracy Requirements for UART Communications"

https://www.maximintegrated.com/en/a...ex.mvp/id/2141

Good find :-)

--
Cheers, Carlos.

T wrote:
On 8/23/19 11:07 PM, Paul wrote:
0 (zero) is 0x30 hex
: (colon) is 0x3a hex

I don't immediately see a pattern there.

Me either. I think something got buggered up on
his CNC machine. The same symptom occurred on two
different USB to RS232 adapters with different chip
sets.

This is driving me nuts. I wish he'd call me
back in so I can kick its ass!


Do you know if the baud rate is fixed ?

Could you start out slower and work up to speed ?

I suppose it would help if the CNC had a manual.
Or, if the part of the machine that controls the
CNC had documentation.

Paul

On 8/24/19 12:52 AM, Paul wrote:
T wrote:
On 8/23/19 11:07 PM, Paul wrote:
0 (zero)Â* is 0x30 hex
: (colon) is 0x3a hex

I don't immediately see a pattern there.

Me either.Â* I think something got buggered up on
his CNC machine.Â* The same symptom occurred on two
different USB to RS232 adapters with different chip
sets.

This is driving me nuts.Â* I wish he'd call me
back in so I can kick its ass!


Do you know if the baud rate is fixed ?

Could you start out slower and work up to speed ?

I suppose it would help if the CNC had a manual.
Or, if the part of the machine that controls the
CNC had documentation.

Â*Â* Paul

Ya, all of that. I hate a challenge interrupted.
He said he only need it to work twice a years, so he
will worry about it then. Hopefully, I
won't go crazy speculating in the mean time!