OT: USB to RS232 converter?

[Robert Roland]

On Tue, 9 Oct 2012 16:01:10 +0100, "N_Cook" <diverse@tcp.co.uk> wrote:

Or the other similar I was looking at has active chipset conversion in the
adapter, but always seems to refer to fast serial links useage, I've not
seen specifically as low as 9600.

The driver will provide you with a virtual serial port. This port's
speed (and other parameters) is configured in the same way you would a
physical serial port.

And whether Prolific or FTDI chipsets, seems to be horses for courses, and
reading around this topic a number of people seem to end up with the wrong
horse.

As Geoffrey explains, the knockoff Prolific chips are troublesome on
newer versions of Windows. If you get a genuine one, you'll be fine.
FTDI and SiLabs also work well in my experience.

If it was possible to slow down the USB then just wasted some driver
download time if no connection emerges

You don't want to slow down the USB data rate. You want to tell the
microcontroller in the converter to transmit and receive data at a
specific rate. As mentioned, you do that just as if it was a physical
serial port. The driver takes care of the rest.
--
RoRo

 

[Franc Zabkar]

On Fri, 12 Oct 2012 10:15:00 +0100, "N_Cook" <diverse@tcp.co.uk> put
finger to keyboard and composed:

Michael A. Terrell <mike.terrell@earthlink.net> wrote in message
news:T6ydneLn5-7tS-rNnZ2dnUVZ_jSdnZ2d@earthlink.com...

N_Cook wrote:

Anyone any idea where there is a live download site, ie not dead links/
google adword junksites, to this hyperterminal version?

htpe63.exe



http://answers.microsoft.com/en-us/windows/forum/windows_7-windows_programs
/does-windows-7-have-hyperterminal-or-an-equivalent/8ca422a1-ca95-4510-87ca-
2ab6bcc7aef7


I will try the win7 compatible one mentioned there. when I get back to it,
currently inundated with a plague of repairs involving blown mains fuses,
perhaps there was mains surges locally

PuTTY is another popular freeware terminal emulator:
http://www.chiark.greenend.org.uk/~sgtatham/putty/

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

 

[N_Cook]

Franc Zabkar <fzabkar@iinternode.on.net> wrote in message
news:eplk781tb4lomukqiiqfjdsnqju3g3l0id@4ax.com...

On Fri, 12 Oct 2012 10:15:00 +0100, "N_Cook" <diverse@tcp.co.uk> put
finger to keyboard and composed:

Michael A. Terrell <mike.terrell@earthlink.net> wrote in message
news:T6ydneLn5-7tS-rNnZ2dnUVZ_jSdnZ2d@earthlink.com...

N_Cook wrote:

Anyone any idea where there is a live download site, ie not dead
links/
google adword junksites, to this hyperterminal version?

htpe63.exe




http://answers.microsoft.com/en-us/windows/forum/windows_7-windows_program
s

/does-windows-7-have-hyperterminal-or-an-equivalent/8ca422a1-ca95-4510-87ca
-
2ab6bcc7aef7


I will try the win7 compatible one mentioned there. when I get back to
it,
currently inundated with a plague of repairs involving blown mains fuses,
perhaps there was mains surges locally

PuTTY is another popular freeware terminal emulator:
http://www.chiark.greenend.org.uk/~sgtatham/putty/

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

I've unzipped the hyperterminal1 one on that page and obtained a USB to
RS232 converter "dongle". The Win7 complient driver opens ok under win7 and
established a serial port as COM3 (in Device Manager) on plugging in.
Opening hyper, set up a 9600 serial. The intended use is 25w D serial . So
far I was a bit rushed and think I had 2 hypers up and operating into COM3 ,
but no LED flicker connecting pins 2 and 3 together on a RS232 checker with
25 to 9 adapter. Hopefully more time available in the next week.

 

[Franc Zabkar]

On Sun, 14 Oct 2012 08:34:50 +0100, "N_Cook" <diverse@tcp.co.uk> put
finger to keyboard and composed:

Franc Zabkar <fzabkar@iinternode.on.net> wrote in message
news:eplk781tb4lomukqiiqfjdsnqju3g3l0id@4ax.com...
On Fri, 12 Oct 2012 10:15:00 +0100, "N_Cook" <diverse@tcp.co.uk> put
finger to keyboard and composed:

Michael A. Terrell <mike.terrell@earthlink.net> wrote in message
news:T6ydneLn5-7tS-rNnZ2dnUVZ_jSdnZ2d@earthlink.com...

N_Cook wrote:

Anyone any idea where there is a live download site, ie not dead
links/
google adword junksites, to this hyperterminal version?

htpe63.exe




http://answers.microsoft.com/en-us/windows/forum/windows_7-windows_program
s

/does-windows-7-have-hyperterminal-or-an-equivalent/8ca422a1-ca95-4510-87ca
-
2ab6bcc7aef7


I will try the win7 compatible one mentioned there. when I get back to
it,
currently inundated with a plague of repairs involving blown mains fuses,
perhaps there was mains surges locally

PuTTY is another popular freeware terminal emulator:
http://www.chiark.greenend.org.uk/~sgtatham/putty/

- Franc Zabkar

I've unzipped the hyperterminal1 one on that page and obtained a USB to
RS232 converter "dongle". The Win7 complient driver opens ok under win7 and
established a serial port as COM3 (in Device Manager) on plugging in.
Opening hyper, set up a 9600 serial. The intended use is 25w D serial . So
far I was a bit rushed and think I had 2 hypers up and operating into COM3 ,
but no LED flicker connecting pins 2 and 3 together on a RS232 checker with
25 to 9 adapter. Hopefully more time available in the next week.

I'm not sure what you are trying to say, but when the Tx and Rx pins
are looped back, you should see an echo for each key that you type. If
there is an echo when the Tx and Rx pins are open, then you would need
to turn off local echo.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

 

[N_Cook]

Franc Zabkar <fzabkar@iinternode.on.net> wrote in message
news:d3tk78tik32vhl45nojb5fpku78unhlb8i@4ax.com...

On Sun, 14 Oct 2012 08:34:50 +0100, "N_Cook" <diverse@tcp.co.uk> put
finger to keyboard and composed:

Franc Zabkar <fzabkar@iinternode.on.net> wrote in message
news:eplk781tb4lomukqiiqfjdsnqju3g3l0id@4ax.com...
On Fri, 12 Oct 2012 10:15:00 +0100, "N_Cook" <diverse@tcp.co.uk> put
finger to keyboard and composed:

Michael A. Terrell <mike.terrell@earthlink.net> wrote in message
news:T6ydneLn5-7tS-rNnZ2dnUVZ_jSdnZ2d@earthlink.com...

I'm not sure what you are trying to say, but when the Tx and Rx pins
are looped back, you should see an echo for each key that you type. If
there is an echo when the Tx and Rx pins are open, then you would need
to turn off local echo.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

My error, only found when I closed down the win7 m/c, and 2 hyper apps to
force closure to.
Just tried again and now LED flicker commensurate with baud setting and
ASCII text echoed to screen for text file "sent" with pins 2,3 xconnected.
So when I can clear the decks and get back to the real use, it should work,
thanks for the assistance in unravelling this topic.

Since CP/M days and dumb terminals I've always checked an RS-232 link with
simple LED checker that I made a mod to, of a switch between p2-p3, to
check that if ascii is sent then ascii is echoed back to the VDU (termed in
those days ISTR) and not garbage on the screen and the LEDs flicker at a
rate varying from slow 110 baud to whatever fast upper setting.
Another reminisce , I first went onto this internet malarcky with a 300 baud
modem

 

[Mike]

In article <d3tk78tik32vhl45nojb5fpku78unhlb8i@4ax.com>,
Franc Zabkar <fzabkar@iinternode.on.net> wrote:

I'm not sure what you are trying to say, but when the Tx and Rx pins
are looped back, you should see an echo for each key that you type. If
there is an echo when the Tx and Rx pins are open, then you would need
to turn off local echo.

YYoouu ddoonn''tt hhaavvee ttoo ttuurrnn iitt ooffff

.... but it helps. If you've got characters appearing with no loopback,
you'll get *two* of everything with a successful loopback.
--
--------------------------------------+------------------------------------
Mike Brown: mjb[-at-]signal11.org.uk | http://www.signal11.org.uk

--- news://freenews.netfront.net/ - complaints: news@netfront.net ---

 

[N_Cook]

This is UK "Maplin" badged 10 quid USB-RS232 converter with Prolific chipset
with win7 on the box and a CDrom. As always? with these adaptors the spec on
the box or manual only refers to speeds up to ... , never down to .... , T
got no help from store "assistant". There was an engineer in the shop when I
was there, saying he uses exactly those ones for updating/transfering from
laptop USB to RS232 industrial process controllers, sometimes at 2400 baud
and usually 9600 baud.
As the assistant said, "I've learnt something today "

Not tried in ernest but setting this , unzipped on win7 starter
http://files.digitizor.com/wp-content/uploads/2009/08/hyperterminal1.zip
to paper tape speed 110 baud the LEDs flicker pedestrianly on the serial
line checker so presumably can go from 110 baud , through the required 9600
to the 500K or whatever

 

[isw]

In article <k5dra1$p8v$2@dont-email.me>, "N_Cook" <diverse@tcp.co.uk>
wrote:

I've unzipped the hyperterminal1 one on that page and obtained a USB to
RS232 converter "dongle". The Win7 complient driver opens ok under win7 and
established a serial port as COM3 (in Device Manager) on plugging in.
Opening hyper, set up a 9600 serial. The intended use is 25w D serial . So
far I was a bit rushed and think I had 2 hypers up and operating into COM3 ,
but no LED flicker connecting pins 2 and 3 together on a RS232 checker with
25 to 9 adapter. Hopefully more time available in the next week.

According to the PL-2303 data sheet (which you can find on line), the
device can be set for any combination of start bits, stop bits, and
parity you might want, and uses a programmable baud rate generator which
covers the range from 75 baud to 1,228,800 baud. Those parameters should
be settable using whatever sort of terminal emulator app you have.

The current capability of the chip's output pins is nowhere near that of
a "real" RS-232 device, and the voltage is likely to be a lot lower, so
it may not be able to make the LEDs in a tester light up. Also, the
signal levels may be inverted from "standard" RS-232.

Isaac

 

[N_Cook]

Geoffrey S. Mendelson <gsm@mendelson.com> wrote in message
news:slrnk7nmla.ti8.gsm@cable.mendelson.com...

isw wrote:
The current capability of the chip's output pins is nowhere near that of
a "real" RS-232 device, and the voltage is likely to be a lot lower, so
it may not be able to make the LEDs in a tester light up. Also, the
signal levels may be inverted from "standard" RS-232.

It's a TTL device.

RS232 is a VOLTAGE interface, with the original spec being -15/+15, then
it
was reduced to -12/+12, and some improperly designed interfaces
send -5/+5.
The voltage must cross 0 volts.


TTL devices are CURRENT interfaces. They use +5 (or 3.3) volts to stop
a current flow, and ground to allow one. Some RS-232 interfaces mistakenly
accept the ground as the same as -12 volts and the +5 as +12.

It is inverted because the RS-232 spec is that -12 is 1, and +12 is 0.

If you want to make a proper RS232 interface from a USB bridge chip, you
need a voltage converter chip the MAX-232 are the most common because they
have built in DC to DC converters to provide the higher voltages of both
polarity.

You have to be careful because some devices have actual RS-232 interfaces,
while others have TTL. Most Japanese, Chinese and Motorola radios have
TTL interfaces, while Tait radios use RS-232.

I don't know about any other devices, except modems, but I'm not sure
anyone has one these days.

Geoff.

--
Geoffrey S. Mendelson, N3OWJ/4X1GM/KBUH7245/KBUW5379
"Owning a smartphone: Technology's equivalent to learning to play
chopsticks on the piano as a child and thinking you're a musician."
(sent to me by a friend)

I measured, no load, -10V on one of the pins of this Maplin/prolific one.
The converter works where intended and the piece of kit can now be taken out
on the road and function changes made via a win7 10 inch notebook pc rather
than win98 desktop machine

 

[N_Cook]

Ian Malcolm <See.My.Sig.for.email@totally.invalid> wrote in message
news:XnsA0ED78C40E1380xDEADBEEF@88.198.244.100...

isw <isw@witzend.com> wrote in
news:isw-515EC4.21184014102012@[216.168.3.50]:


The current capability of the chip's output pins is nowhere near that
of a "real" RS-232 device, and the voltage is likely to be a lot
lower, so it may not be able to make the LEDs in a tester light up.
Also, the signal levels may be inverted from "standard" RS-232.

Isaac

I have the Maplin ZP43W Prolific PL2303 chipset USB <==> serial adaptor,
which as I *think* it is the only one of its type in their range so is
almost certainly the same as N_Cook's one.

It certainly has enough drive capability to light high efficiency bicolour
LEDs while maintaining adequate signal levels for a MAX232CPE chip. My
RS232 <==> TTL serial level converter board's LEDs have 8.2K series
resistors and I am seeing approximately +/- 6.2V levels when loaded by the
LEDs and the MAX232. Off-load I see +/- 6.4V levels.


--
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
[at]=@, [dash]=- & [dot]=. *Warning* HTML & >32K emails --> NUL

I forgot it did have the load of the checker LEDs

Removed a sticker and can just read through the blue translucent plastic, 28
pinner is PL2303 then suffix HK or HX perhaps, the other 28 pinner or so
not readable
E no. is clear
E315599

 

[Geoffrey S. Mendelson]

isw wrote:

The current capability of the chip's output pins is nowhere near that of
a "real" RS-232 device, and the voltage is likely to be a lot lower, so
it may not be able to make the LEDs in a tester light up. Also, the
signal levels may be inverted from "standard" RS-232.

It's a TTL device.

RS232 is a VOLTAGE interface, with the original spec being -15/+15, then it
was reduced to -12/+12, and some improperly designed interfaces send -5/+5.
The voltage must cross 0 volts.


TTL devices are CURRENT interfaces. They use +5 (or 3.3) volts to stop
a current flow, and ground to allow one. Some RS-232 interfaces mistakenly
accept the ground as the same as -12 volts and the +5 as +12.

It is inverted because the RS-232 spec is that -12 is 1, and +12 is 0.

If you want to make a proper RS232 interface from a USB bridge chip, you
need a voltage converter chip the MAX-232 are the most common because they
have built in DC to DC converters to provide the higher voltages of both
polarity.

You have to be careful because some devices have actual RS-232 interfaces,
while others have TTL. Most Japanese, Chinese and Motorola radios have
TTL interfaces, while Tait radios use RS-232.

I don't know about any other devices, except modems, but I'm not sure
anyone has one these days.

Geoff.

--
Geoffrey S. Mendelson, N3OWJ/4X1GM/KBUH7245/KBUW5379
"Owning a smartphone: Technology's equivalent to learning to play
chopsticks on the piano as a child and thinking you're a musician."
(sent to me by a friend)

 

[Ian Malcolm]

isw <isw@witzend.com> wrote in
news:isw-515EC4.21184014102012@[216.168.3.50]:

The current capability of the chip's output pins is nowhere near that
of a "real" RS-232 device, and the voltage is likely to be a lot
lower, so it may not be able to make the LEDs in a tester light up.
Also, the signal levels may be inverted from "standard" RS-232.

Isaac

I have the Maplin ZP43W Prolific PL2303 chipset USB <==> serial adaptor,

which as I *think* it is the only one of its type in their range so is
almost certainly the same as N_Cook's one.

It certainly has enough drive capability to light high efficiency bicolour
LEDs while maintaining adequate signal levels for a MAX232CPE chip. My
RS232 <==> TTL serial level converter board's LEDs have 8.2K series
resistors and I am seeing approximately +/- 6.2V levels when loaded by the
LEDs and the MAX232. Off-load I see +/- 6.4V levels.


--
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
[at]=@, [dash]=- & [dot]=. *Warning* HTML & >32K emails --> NUL