RsK wrote:
> Please anybody can give me a brief idea that using oscilloscope how i
> can capture the waveform on a serial link, tranmitting the ASCII letter
> 'R'  with 1 start bit, 1 end bit, 1 parity, with 1200 Baud.?
> 
> I have connected oscilloscope with serial interface then? then selected
> the CH1 & CH2 then changed some setting on oscilloscope for RS232 , the
> wt to do?
> 
> waiting for ur reply?
> 
> regards
> 

To assist in your reading the replies here, I posted a PDF of a 
simulated scope trace of the letter 'R' (assuming it to be the only 
transmission) on RS232.

Cheers

PeteS

On a sunny day (18 Nov 2006 07:26:52 -0800) it happened "RsK"
<r...@gmail.com> wrote in
<1...@e3g2000cwe.googlegroups.com>:

Now what you will see is one start bit, the ASCII code for 'R', and a parity bit.
the ASCII code for 'R' is 52 hex, or in binary, with MSB first:
0101 0010

Correction, seems it is transmitted LSB first:
see
 http://www.acumeninstruments.com/Support/documentation/SerialPortBasics/index_pg6.shtml

On 2006-11-18, Jerry Avins <j...@ieee.org> wrote:
> John Popelish wrote:
>> RsK wrote:
>>> Please anybody can give me a brief idea that using oscilloscope how i
>>> can capture the waveform on a serial link, tranmitting the ASCII letter
>>> 'R'  with 1 start bit, 1 end bit, 1 parity, with 1200 Baud.?
>>>
>>> I have connected oscilloscope with serial interface then? then selected
>>> the CH1 & CH2 then changed some setting on oscilloscope for RS232 , the
>>> wt to do?
>>>
>>> waiting for ur reply?
>> 
>> You need a terminal emulator program to capture the character stream 
>> into a file (that you name).  Depending on what file format you set the 
>> scope to use to format the image, you use an image viewer to look at the 
>> resulting file.  The details are dependent on the scope model and the 
>> terminal emulator program you have.
>
> Does the OP want to see the letter, or the waveform? The ASCII letter R 
> in hexadecimal is 52. RS-232 standard levels are +/- 12 volts, with 
> "mark" = +12 and "space" = -12. 

T'other way round. mark is negative.

-- 

Bye.
   Jasen

On 2006-11-18, RsK <r...@gmail.com> wrote:
> Please anybody can give me a brief idea that using oscilloscope how i
> can capture the waveform on a serial link, tranmitting the ASCII letter
> 'R'  with 1 start bit, 1 end bit, 1 parity, with 1200 Baud.?
>
> I have connected oscilloscope with serial interface then? then selected
> the CH1 & CH2 then changed some setting on oscilloscope for RS232 , the
> wt to do?

assuming you're using 7 data bits even parity and one stop bit 
(which is a fairly common line protocol)

idle line is negative , then 7 data bits (1 is negative 0 is positive)
then the stop parity and then the stop bit.

 start            0
 data  (lsb first) 0100101
 parity                   1
 stop                      1
 

set you scope for positive triggering, and about 2ms/division scan rate
and 5V/division vertical gain (assuming a "X10" probe)
connect it to pin 3 of the 9-pin serial port, pin 5 is your ground.
you'll get something like this. 

(view with fixed font)


    S  D0  D1  D2  D3  D4  D5  D6  P   S
    
  --------    --------    ----                                         
          ----        ----    -------------...
                                            
                                            |
after the stop bit the voltage will stay low until
the start bit of the next symbol...

if your terminal program has such a feature you can program one of the
function keys to send RRR and then wedge it down
which will give a brighter trace and also show the start bit coming 
right after the stop bit.

with the keyboar repeat at about 16 per second (fairly normal) you'll see
some idle time and
some start bit immediatley after the stop bit.

Bye.
   Jasen

jasen wrote:
> On 2006-11-18, Jerry Avins <j...@ieee.org> wrote:
>> John Popelish wrote:
>>> RsK wrote:
>>>> Please anybody can give me a brief idea that using oscilloscope how i
>>>> can capture the waveform on a serial link, tranmitting the ASCII letter
>>>> 'R'  with 1 start bit, 1 end bit, 1 parity, with 1200 Baud.?
>>>>
>>>> I have connected oscilloscope with serial interface then? then selected
>>>> the CH1 & CH2 then changed some setting on oscilloscope for RS232 , the
>>>> wt to do?
>>>>
>>>> waiting for ur reply?
>>> You need a terminal emulator program to capture the character stream 
>>> into a file (that you name).  Depending on what file format you set the 
>>> scope to use to format the image, you use an image viewer to look at the 
>>> resulting file.  The details are dependent on the scope model and the 
>>> terminal emulator program you have.
>> Does the OP want to see the letter, or the waveform? The ASCII letter R 
>> in hexadecimal is 52. RS-232 standard levels are +/- 12 volts, with 
>> "mark" = +12 and "space" = -12. 
> 
> T'other way round. mark is negative.

Yes. Sorry. Sometimes the TTL version sticks in my head. It's been a 
long time.

Jerry
-- 
Engineering is the art of making what you want from things you can get.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

Jerry Avins wrote:

 From provate email. because I don't see it here:

Patrick Klos wrote:
 > To: j...@ieee.org
 > Subject: Re: how to do it? RS232
 > Newsgroups: 
comp.robotics.misc,sci.engr.control,sci.electronics.basics,alt.engineering.electrical,sci.electronics.design
 > In-Reply-To: <f...@rcn.net>
 > References: <1...@e3g2000cwe.googlegroups.com> 
<h...@adelphia.com> 
<p...@rcn.net> 
<9NG7h.10349$F...@newsfe2-win.ntli.net>
 > Organization: Klos Technologies, Inc.
 > Cc:
 >
 > In article <f...@rcn.net> you write:
 >> PeteS wrote:
 >>
 >>   ...
 >>
 >>> Minor correction; a marking line is -3 <> -15V (logical 1) :)
 >> Of course. Sometimes my head gets stuffed with current loop facts.
 >>
 >> Thanks.
 >
 > Correct me if I'm wrong, but I'm pretty sure the serial bits are
 > transmitted LSB first?  Your picture gave the impression that MSB
 > is sent first.  Am I remembering that correctly?
 >
 > Patrick
 > =========== For PPP Protocol Analysis, check out PacketView Pro! 
===========
 >     Patrick Klos                           Email: p...@klos.com
 >     Klos Technologies, Inc.                Web:   http://www.klos.com/
 > 
============================================================================

Patrick,

These followups belong in the newsgroup with the rest of the thread. The 
most significant bit is sent first and appears on the left of the scope 
trace. http://francis.courtois.free.fr/jc1/serial/Basics/RawSignals.html 
might be helpful

-- 
A quitter never wins. A winner never quits. A fool never does either.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

RsK wrote:
> Please anybody can give me a brief idea that using oscilloscope how i
> can capture the waveform on a serial link, tranmitting the ASCII letter
> 'R'  with 1 start bit, 1 end bit, 1 parity, with 1200 Baud.?

Your can see the waveform for any serial data with this program:

http://www.miscel.dk/MiscEl/miscelSerialCommunication.html

If your want to capture it live on an oscilloscope your need a scope 
with storage (a PC based digital scope is fine) or your must send the 
data repeatedly.

"HKJ" <h...@miscel.dk> wrote in message
news:45601883$0$182$1...@dreader1.cybercity.dk...
[...]
>
> Your can see the waveform for any serial data with this program:
>
> http://www.miscel.dk/MiscEl/miscelSerialCommunication.html
>
Nice idea you have there, hope you stick with it.
Use it when I'm just too bone idle to pick up the calculator.
The "Attenuators" section (nice!). Any chance of offering say 3 digits of
resistor precision in addition to the E12 rounding?. Or maybe offer an
E12/E24/E96 rounding option?.
john



-- 
Posted via a free Usenet account from http://www.teranews.com

"john jardine" <j...@jjdesigns.fsnet.co.uk> wrote in message
news:45607fc7$0$21121$8...@free.teranews.com...
>
> "HKJ" <h...@miscel.dk> wrote in message
> news:45601883$0$182$1...@dreader1.cybercity.dk...
> [...]
> >
> > Your can see the waveform for any serial data with this program:
> >
> > http://www.miscel.dk/MiscEl/miscelSerialCommunication.html
> >
[...]
> The "Attenuators" section (nice!). Any chance of offering say 3 digits of
> resistor precision in addition to the E12 rounding?. Or maybe offer an
> E12/E24/E96 rounding option?.

Ignore that. Just spotted all the rounding options :)



-- 
Posted via a free Usenet account from http://www.teranews.com

john jardine wrote:
> "HKJ" <h...@miscel.dk> wrote in message
> news:45601883$0$182$1...@dreader1.cybercity.dk...
> [...]
>> Your can see the waveform for any serial data with this program:
>>
>> http://www.miscel.dk/MiscEl/miscelSerialCommunication.html
>>
> Nice idea you have there, 

Thanks,

> hope you stick with it.

I plan to.


> Use it when I'm just too bone idle to pick up the calculator.
> The "Attenuators" section (nice!). Any chance of offering say 3 digits of
> resistor precision in addition to the E12 rounding?. Or maybe offer an
> E12/E24/E96 rounding option?.


It is already there, use the "System, Preferede component" page to 
select it.
http://www.miscel.dk/MiscEl/miscelPreferedComponents.html

In the System menu your also have a search function, that can be used to 
locate the correct page to do something. Write E96 in it at it will tell 
your to look at the "Prefered component" page.