A Windows XP help forum. PCbanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » PCbanter forum » Microsoft Windows XP » Hardware and Windows XP
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

USB to RS232 to USB adapter needed



 
 
Thread Tools Display Modes
  #1  
Old February 16th 09, 05:05 PM posted to microsoft.public.windowsxp.hardware
eljainc
external usenet poster
 
Posts: 60
Default USB to RS232 to USB adapter needed

Hello,

I am trying to send RS232 data from two notebooks that do not have
serial ports. I know there are USB to serial (RS232) adapters
available. These allow communications to occur through a virtual
serial port. Now, what I need is a USB to USB RS232 serial cable, that
allows serial transmissions to occur, but via USB connections.

Can someone please point me in the right direction?

Thanks
Mike
Ads
  #2  
Old February 16th 09, 05:17 PM posted to microsoft.public.windowsxp.hardware
roger
external usenet poster
 
Posts: 93
Default USB to RS232 to USB adapter needed

Gogle it:
http://www.google.com.pe/search?rlz=...+RS232+adaptor

eljainc wrote:
Hello,

I am trying to send RS232 data from two notebooks that do not have
serial ports. I know there are USB to serial (RS232) adapters
available. These allow communications to occur through a virtual
serial port. Now, what I need is a USB to USB RS232 serial cable, that
allows serial transmissions to occur, but via USB connections.

Can someone please point me in the right direction?

Thanks
Mike

  #3  
Old February 16th 09, 08:08 PM posted to microsoft.public.windowsxp.hardware
Paul
external usenet poster
 
Posts: 18,275
Default USB to RS232 to USB adapter needed

eljainc wrote:
Hello,

I am trying to send RS232 data from two notebooks that do not have
serial ports. I know there are USB to serial (RS232) adapters
available. These allow communications to occur through a virtual
serial port. Now, what I need is a USB to USB RS232 serial cable, that
allows serial transmissions to occur, but via USB connections.

Can someone please point me in the right direction?

Thanks
Mike


There is an example here. I picked this one, to demonstrate
the physical appearance of such a cable. Note that there is a
"blob" in the center of the cable, and identical USB connectors
on each end. The blob being dead center on the cable, hints
at its unique characteristics (some buffer cables have a
blob as well, but the blob is very close to one end of the
cable).

http://www.newegg.com/Product/Produc...82E16812200198

Software is the important part of such a linking device. There
is a chip, inside the blob. Its job is to logically isolate
the two sides - USB is not designed for direct peer to peer
connections. What one computer sees, is a USB chip with a
FIFO peripheral buffer in it. The computer writes to the FIFO buffer.
The "other side" of the chip, then forwards what shows up
in the FIFO, to the other computer. The other computer is
regularly polling the device, to see if anything has shown
up. So the chip functions as a "bidirectional mailbox".

Computer A ------ FIFO ----------- Computer B
------ FIFO -----------

Windows does not understand what this device does. It
takes a software overlay or driver, to make the device
do something useful. One instance of this, may be
referred to, as a member of the "Laplink" family.

I've seen two options offered by such software.
One, offers a complete TCP/IP stack. That fools Windows
into thinking the USB blob is a network interface. If
you enabled File Sharing on one of the computers, and
used the TCP/IP version of software, then copying files
would be the same as normal File Sharing.

The other version of software, implements a "File Transfer"
wizard interface. There is no TCP/IP stack in that case, and
no network addresses are used. You get a dialog box similar
to some of the old FTP transfer programs. One side of the window
shows the local disk selected, the other side shows the remote
device and its disk. You can copy files via that window,
in the same way you would have with the old FTP software.

So, in purchasing these things, you want

1) Software CD. Should include documentation. Preferably,
there should be a web site that details what the software
will do for you. Just purchasing the "cable with blob"
by itself, doesn't guarantee it will do anything. The
hardware is pretty useless, without good software. A
software package that includes both the TCP/IP stack,
and the Transfer Wizard style software, offers the most
flexibility. (The Newegg page mentions some capability
built into Windows called "Easy Transfer", but I have
no idea what they're referring to there. A good software
package, should make it so you can connect a Win98 machine
to your other computer, and transfer files.)

2) The "blobs" come in two flavors. The original one was
USB 1.1 speed only. It would transfer your files, but
at only 1 megabyte per second. Later, a USB2 version of
the chip was made, that really worked at USB2 rates.
One company decided to make a copy of this chip, but
I think they were slapped with patent litigation and
had to discontinue their product. I don't know who, if
anyone, still makes the chips. This knowledge is only
important if you're buying from Ebay, and some scammer
has located some of the older, slower products.

Another example here.

http://www.usbfiletransfer.com/

This is an example of a chip used inside the blob. This
one is USB 1.1 rate only. I'm including this, to give
a better diagram of the FIFOs used to isolate the two
computers from one another. Notice how the chip maker
promises drivers for a version of Win95 (and that is
a typical reason why people want these cables - for
transferring files between computers that share very
little in common).

http://www.prolific.com.tw/eng/Products.asp?ID=19

HTH,
Paul
  #4  
Old February 16th 09, 08:11 PM posted to microsoft.public.windowsxp.hardware
Patrick Keenan
external usenet poster
 
Posts: 4,415
Default USB to RS232 to USB adapter needed

"eljainc" wrote in message
...
Hello,

I am trying to send RS232 data from two notebooks that do not have
serial ports. I know there are USB to serial (RS232) adapters
available. These allow communications to occur through a virtual
serial port. Now, what I need is a USB to USB RS232 serial cable, that
allows serial transmissions to occur, but via USB connections.

Can someone please point me in the right direction?

Thanks
Mike


I have to use this kind of thing regularly, and they *are* the USB to serial
adapters you mention. You just need to add a standard serial cable as the
missing component.

These are readily available starting around $15 or so. They come with a
driver disk that you will need to use. You can also get ExpressCard
versions (ExpressCard is the replacement for PCMCIA cards) but these are
much more expensive.

Note that these units are *not* all the same quality, and on some systems
(such as Dell laptops) only specific brands of adapter (IIRC it's CoolGear),
meaning specific chipsets, will work reliably. Other units can lead to
temporary system freezing.

To use serial cables, you just need a pair of the USB-serial adapters and
the serial cables, plus whatever crosswire adapters are needed. In the
case of real-time court reporting equipment, most of which still requires
serial ports, specific crosswired adapters are required depending on the
brand of the distribution kit. So, there are at least three readily
available components required in the setup. Crosswire adapters may or may
not be required or easy to get; in some cases you might need a standard
null-modem adapter. You should be able to determine this from the
documentation for the software that requires the serial connection.

Alternately, you can ditch all these cables and adapters completely by using
Serial-to-TCP redirector software. This is a small redirector utility
that's run on each system, and each license costs in the $100 range, and you
need at least two - there are free demo versions so you can try it out.
The demos are full-function but time-limited, and I've used this on both XP
and Vista successfully and reliably.

Once it's installed and configured, you use the existing network cabling *or
wireless connection* and do not have to bother with serial cabling. This
can work very well, and is what we have gone to. An example is TCP-Com, by
TalTech. Google "Serial to TCP" for more information.

HTH
-pk


  #5  
Old February 16th 09, 08:31 PM posted to microsoft.public.windowsxp.hardware
Patrick Keenan
external usenet poster
 
Posts: 4,415
Default USB to RS232 to USB adapter needed

"Paul" wrote in message
...
eljainc wrote:
Hello,

I am trying to send RS232 data from two notebooks that do not have
serial ports. I know there are USB to serial (RS232) adapters
available. These allow communications to occur through a virtual
serial port. Now, what I need is a USB to USB RS232 serial cable, that
allows serial transmissions to occur, but via USB connections.

Can someone please point me in the right direction?

Thanks
Mike


There is an example here. I picked this one, to demonstrate
the physical appearance of such a cable. Note that there is a
"blob" in the center of the cable, and identical USB connectors
on each end. The blob being dead center on the cable, hints
at its unique characteristics (some buffer cables have a
blob as well, but the blob is very close to one end of the
cable).

http://www.newegg.com/Product/Produc...82E16812200198

Software is the important part of such a linking device. There
is a chip, inside the blob. Its job is to logically isolate
the two sides - USB is not designed for direct peer to peer
connections. What one computer sees, is a USB chip with a
FIFO peripheral buffer in it. The computer writes to the FIFO buffer.
The "other side" of the chip, then forwards what shows up
in the FIFO, to the other computer. The other computer is
regularly polling the device, to see if anything has shown
up. So the chip functions as a "bidirectional mailbox".

Computer A ------ FIFO ----------- Computer B
------ FIFO -----------

Windows does not understand what this device does. It
takes a software overlay or driver, to make the device
do something useful. One instance of this, may be
referred to, as a member of the "Laplink" family.

I've seen two options offered by such software.
One, offers a complete TCP/IP stack. That fools Windows
into thinking the USB blob is a network interface. If
you enabled File Sharing on one of the computers, and
used the TCP/IP version of software, then copying files
would be the same as normal File Sharing.

The other version of software, implements a "File Transfer"
wizard interface. There is no TCP/IP stack in that case, and
no network addresses are used. You get a dialog box similar
to some of the old FTP transfer programs. One side of the window
shows the local disk selected, the other side shows the remote
device and its disk. You can copy files via that window,
in the same way you would have with the old FTP software.

So, in purchasing these things, you want

1) Software CD. Should include documentation. Preferably,
there should be a web site that details what the software
will do for you. Just purchasing the "cable with blob"
by itself, doesn't guarantee it will do anything. The
hardware is pretty useless, without good software. A
software package that includes both the TCP/IP stack,
and the Transfer Wizard style software, offers the most
flexibility. (The Newegg page mentions some capability
built into Windows called "Easy Transfer", but I have
no idea what they're referring to there. A good software
package, should make it so you can connect a Win98 machine
to your other computer, and transfer files.)

2) The "blobs" come in two flavors. The original one was
USB 1.1 speed only. It would transfer your files, but
at only 1 megabyte per second. Later, a USB2 version of
the chip was made, that really worked at USB2 rates.
One company decided to make a copy of this chip, but
I think they were slapped with patent litigation and
had to discontinue their product. I don't know who, if
anyone, still makes the chips. This knowledge is only
important if you're buying from Ebay, and some scammer
has located some of the older, slower products.

Another example here.

http://www.usbfiletransfer.com/

This is an example of a chip used inside the blob. This
one is USB 1.1 rate only. I'm including this, to give
a better diagram of the FIFOs used to isolate the two
computers from one another. Notice how the chip maker
promises drivers for a version of Win95 (and that is
a typical reason why people want these cables - for
transferring files between computers that share very
little in common).

http://www.prolific.com.tw/eng/Products.asp?ID=19

HTH,
Paul


As I understand it, this cable and its software, while useful, doesn't
create an actual or virtual serial port. Depending on the unknown
application the OP has to use, that can be extremely important, and a
deal-killer.

For example, most real-time court reporting systems still output *only* to a
serial port (or a specific server you might pay tens of thousands of dollars
for). They don't know anything at all about what to do with an IP address
or a USB port, or a file transfer window. We have regularly used the USB
to serial adapters the OP already knows about - you just need the serial
cabling and whatever crosswire adapters are specific to the distribution
kit, or even better, Serial to TCP redirector software that allows you to
use existing network structures, wired or wireless. These create a virtual
serial port that the software can't distinguish from hardware. Works
great, and removes the need for extra cabling entirely.

Hard to say, though, without knowing what the OP is actually trying to
accomplish and the software in question.

HTH
-pk


  #6  
Old February 16th 09, 09:45 PM posted to microsoft.public.windowsxp.hardware
eljainc
external usenet poster
 
Posts: 60
Default USB to RS232 to USB adapter needed

Very informative replies. Thanks

We actually have used the USB-USB network bridge (the purple USB 1.1
version from Laplink). While they had
their usefulness for a previous purpose, I am not sure if they will
work for this case, unless we do use a serial to
IP redirector in conjunction with this device. If that is the case the
laplink USB-USB network bridge wouldn't be
needed.

Would it be possible to piggyback two of these USB to RS232 devices
together so that each end would have the
USB connction, then connect the two DB9 connectors together. Would
this present a major conflict or could the
device data be transferred both directions? Just a thought.

  #7  
Old February 17th 09, 12:12 AM posted to microsoft.public.windowsxp.hardware
Paul
external usenet poster
 
Posts: 18,275
Default USB to RS232 to USB adapter needed

eljainc wrote:
Very informative replies. Thanks

We actually have used the USB-USB network bridge (the purple USB 1.1
version from Laplink). While they had
their usefulness for a previous purpose, I am not sure if they will
work for this case, unless we do use a serial to
IP redirector in conjunction with this device. If that is the case the
laplink USB-USB network bridge wouldn't be
needed.

Would it be possible to piggyback two of these USB to RS232 devices
together so that each end would have the
USB connction, then connect the two DB9 connectors together. Would
this present a major conflict or could the
device data be transferred both directions? Just a thought.


Sure. Either idea will work. The "blob" idea offers high thruput,
but requires the right software to get it to work. (I don't know
if USB.org has defined an official class definition for the thing
or not.)

The USB-to-serial idea has the advantage that it looks like a serial
port, so more software may work with it. Just make sure you use the
right DB-9 to DB-9 cable to connect them together, and that the
devices have the feature set you're looking for (hardware flow control,
high baud rates, or whatever).

You can get some pretty fancy ones.

http://www.ftdichip.com/Products/FT232BM.htm

Paul
  #8  
Old February 17th 09, 12:14 AM posted to microsoft.public.windowsxp.hardware
Patrick Keenan
external usenet poster
 
Posts: 4,415
Default USB to RS232 to USB adapter needed

"eljainc" wrote in message
...
Very informative replies. Thanks

We actually have used the USB-USB network bridge (the purple USB 1.1
version from Laplink). While they had
their usefulness for a previous purpose, I am not sure if they will
work for this case, unless we do use a serial to
IP redirector in conjunction with this device. If that is the case the
laplink USB-USB network bridge wouldn't be
needed.

Would it be possible to piggyback two of these USB to RS232 devices
together so that each end would have the
USB connction, then connect the two DB9 connectors together. Would
this present a major conflict or could the
device data be transferred both directions? Just a thought.


That's a case where you might, or might not, need a null-modem adapter,
which simply flips a couple of wires to allow direct connection like this.
The documentation for the app should tell you this. IIRC, the old LapLink
serial cables were essentially null-modem cables.

Despite the cost, I can recommend the serial-to-TCP redirector software.
It can bypass a lot of issues and considerations common to serial devices,
and add significant features, such as longer cable runs, more connecting
systems and net broadcast; similarly, there can be security issues.

Check out the free demo versions; these usually work for two weeks or so,
plenty of time to see if it works for you (and possibly to complete the
task). They install in minutes.

A big factor in what will work best is whether you absolutely have to use a
serial port for the app in question.

HTH
-pk


  #9  
Old February 17th 09, 01:42 PM posted to microsoft.public.windowsxp.hardware
M.I.5¾
external usenet poster
 
Posts: 2,722
Default USB to RS232 to USB adapter needed


"eljainc" wrote in message
...
Hello,

I am trying to send RS232 data from two notebooks that do not have
serial ports. I know there are USB to serial (RS232) adapters
available. These allow communications to occur through a virtual
serial port. Now, what I need is a USB to USB RS232 serial cable, that
allows serial transmissions to occur, but via USB connections.

Can someone please point me in the right direction?


There are many of these devices available and googling 'USB to RS232' only
gets you a mere 5,830,000 hits. However, anecdotal evidence suggest that
although these devices work well most of the time, the odd bit of software
is ocassionally encountered on ocassion that will not operate well or at all
with these converters.


  #10  
Old June 22nd 09, 06:00 AM posted to microsoft.public.windowsxp.hardware
GR Aust
external usenet poster
 
Posts: 2
Default USB to RS232 to USB adapter needed

All very interesting. I have been using an ATEN UC232a converter for dumping
data into my XP laptop. This converter has performed fine until the past few
weeks. I now cannot download via the converter. I keep getting 'com port
may be in use' error. This is no matter what port I select. I have also
confirmed what port the unit is running on via Device manager with still no
success.

I am thinking a recent windows update has effected. I do not know the exact
date that this occurred as I used the link successfully 4 weeks or so ago.
Therefore I do not wish to roll my system back that far. I will consider
using a new converter if I know it will work today. I have sent several
emails to ATEN without a reply to date.

Any suggestions are appreciated

"M.I.5¾" wrote:


"eljainc" wrote in message
...
Hello,

I am trying to send RS232 data from two notebooks that do not have
serial ports. I know there are USB to serial (RS232) adapters
available. These allow communications to occur through a virtual
serial port. Now, what I need is a USB to USB RS232 serial cable, that
allows serial transmissions to occur, but via USB connections.

Can someone please point me in the right direction?


There are many of these devices available and googling 'USB to RS232' only
gets you a mere 5,830,000 hits. However, anecdotal evidence suggest that
although these devices work well most of the time, the odd bit of software
is ocassionally encountered on ocassion that will not operate well or at all
with these converters.



  #11  
Old June 22nd 09, 06:00 AM posted to microsoft.public.windowsxp.hardware
GR Aust
external usenet poster
 
Posts: 2
Default USB to RS232 to USB adapter needed

All very interesting. I have been using an ATEN UC232a converter for dumping
data into my XP laptop. This converter has performed fine until the past few
weeks. I now cannot download via the converter. I keep getting 'com port
may be in use' error. This is no matter what port I select. I have also
confirmed what port the unit is running on via Device manager with still no
success.

I am thinking a recent windows update has effected. I do not know the exact
date that this occurred as I used the link successfully 4 weeks or so ago.
Therefore I do not wish to roll my system back that far. I will consider
using a new converter if I know it will work today. I have sent several
emails to ATEN without a reply to date.

Any suggestions are appreciated

"M.I.5¾" wrote:


"eljainc" wrote in message
...
Hello,

I am trying to send RS232 data from two notebooks that do not have
serial ports. I know there are USB to serial (RS232) adapters
available. These allow communications to occur through a virtual
serial port. Now, what I need is a USB to USB RS232 serial cable, that
allows serial transmissions to occur, but via USB connections.

Can someone please point me in the right direction?


There are many of these devices available and googling 'USB to RS232' only
gets you a mere 5,830,000 hits. However, anecdotal evidence suggest that
although these devices work well most of the time, the odd bit of software
is ocassionally encountered on ocassion that will not operate well or at all
with these converters.



 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is Off
HTML code is Off






All times are GMT +1. The time now is 05:45 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 PCbanter.
The comments are property of their posters.