RS232 to USB converter

[Bjarne Joergensen]

Hi

I am looking for a RS232 to USB converter and can't find one.

It's not for Labview but and old PC with Win98 and Modula2 SW .

I have to test a new little divice that we produce. The old device are with RS232 connection and the new device with USB.

If I could get a converter to plug in the old PC's serial port and put the USB device in the converter, it would be the cheapest way.

We only produce 200 pr. year of the new device (price pr. unit 40$) so it's to expencive to by a new PC for the purpose.

hope anyone can help me.

regards Bjarne

[Cat]

I am looking for a RS232 to USB converter and can't find one.

Hmm... lots of USB port -to- DB9 device converters out there, not so many DB9 port - to - USB device converters.

Do you have room in your PC for a USB card (PCI)? You can get one of those for under $20.

[PaulG.]

I picked up a serial port to USB converter at an Office Max or similar store about a year ago.

Edited July 10, 2009 by PaulG.

[JohnRH]

I really don't they such a device exists. (I could be wrong)

As already suggested you could add a USB PCI card.

One other option might be ethernet to usb.

However, this sounds to me like an excuse to upgrade the PC!

Edited July 10, 2009 by JohnRH

[shoneill]

Hi

I am looking for a RS232 to USB converter and can't find one.

It's not for Labview but and old PC with Win98 and Modula2 SW .

I have to test a new little divice that we produce. The old device are with RS232 connection and the new device with USB.

If I could get a converter to plug in the old PC's serial port and put the USB device in the converter, it would be the cheapest way.

We only produce 200 pr. year of the new device (price pr. unit 40$) so it's to expencive to by a new PC for the purpose.

hope anyone can help me.

regards Bjarne

If I understood correctly you want to connect one RS-232 Device with a USB Device, without a computer between?

I don't understand how this is supposed to work on a technical level. USB and Serial have (Aside from the "S" part in USB name) nothing in common.

Shane.

Edited July 11, 2009 by shoneill

[Michael Aivaliotis]

This reminds me of those posts we used to get on LAVA regarding doing DAQ with the parallel port. Win98? Modula-2? Give me a break! If you can't afford the equipment needed to test a device you're manufacturing then I would re-evaluate your business plan...

[Cat]

If I understood correctly you want to connect one RS-232 Device with a USB Device, without a computer between?

I don't understand how this is supposed to work on a technical level. USB and Serial have (Aside from the "S" part in USB name) nothing in common.

I believe Bjarne wants to connect a USB device to a computer that is so old it only has a serial port and no USB ports. I'm not sure there is such a converter available (there are multiple converters for going the other way).

This reminds me of those posts we used to get on LAVA regarding doing DAQ with the parallel port.

BTDT. Long before LAVA was born.

[Bjarne Joergensen]

Hi All

Thanks for the replyes

I admit that the question was a quick one that I got to answer friday afternoon, before I went on hollyday.

So I didn't have so much time to find a lot of solutions.

Hmm... lots of USB port -to- DB9 device converters out there, not so many DB9 port - to - USB device converters.

Do you have room in your PC for a USB card (PCI)? You can get one of those for under $20.

About the PCI solutions. Yes there are room for that but I don't know if Modula can talk with USB?

Maybe it can if the USB device act like a serial device. Then I only need drivers for Win98.

I really don't they such a device exists. (I could be wrong)

As already suggested you could add a USB PCI card.

One other option might be ethernet to usb.

However, this sounds to me like an excuse to upgrade the PC!

Yes, it is a excuse for not upgrating the PC!. We got at test runing now with some other products and we will not upgrade them to a newer platform(product-lifetime i limited).

If you can't afford the equipment needed to test a device you're manufacturing then I would re-evaluate your business plan...

Yes Michael, maybe we should do that, but that is not my decision. By the way as I mentioned, we shall produce max. 200 pr. year(maybe only the first 3 years, then the number will drop) with a costprice of 40$. A new PC (I can only use standard PC's that our IT department has aproved) and development/inplementation cost will be around 3800$(danish prices) resulting in extra 18$ pr. unit the first year!

There are a lot of other questions to handle according to the production setup.

I will be back with the solutions after my hollyday.

Regards Bjarne

Edited July 13, 2009 by Bjarne Joergensen

[George Pollock]

For RS-232 / USB conversions, I suggest you make the acquaintance of "Newegg.com", a supplier of all sorts of computer related stuff. I've gotten a couple of convrtors from them, at something like $35. I've used them to drive a cFP backplane controller with RS-232 from the computer's USB port.

That is a good general fix, by the way. There is a lot of legacy hardware out there that has RS-232 ports. And, while your computer probably has an RS-232 port, it is probably only got one. USB expansion ports are cheap, so you can generate as many RS-232 ports, using converters, as you need.

By the way, if you are using RS-232, be mindful of the age and original intent of that standard. Do not plan on long cable runs or high baud rates without careful research.

[crelf]

I've gotten a couple of convrtors from them, at something like $35. I've used them to drive a cFP backplane controller with RS-232 from the computer's USB port.

I think what Bjarne is after is something that will allow him to plug a USB device into the RS-232 port on his PC, not the other way around.

[RalcoBe]

Why not PCI to Usb, or in the case of an old laptop, a PCMCIA to USB converter?

RS232 has too little possibilities to decently drive all USB devices,

where PCI and PCMCIA have less problems with it.

Costs 10 to 40 eur

.

Edited April 20, 2010 by RalcoBe

[Rolf Kalbermatter]

Why not PCI to Usb, or in the case of an old laptop, a PCMCIA to USB converter?

RS232 has too little possibilities to decently drive all USB devices,

where PCI and PCMCIA have less problems with it.

Costs 10 to 40 eur

.

Because with the USB interface in your computer you are possibly not even halfway done. You need the driver too. Maybe the device installs itself as USB-COMM device which modern computers will install as virtual RS-232. But I'm really not sure USB was that major and far along when Windows 98 was released so even if the device is a USB-COMM class device the Windows 98 computer may not recognize and install it as Windows serial port device.

If it is not an USB-COMM class device then you would need the according system drivers for Windows 98 (.vxd which are different than the drivers needed for NT based Windows systems such as 2000, XP and newer) and then also create a Modula2 module to access that driver.

But manufacturing a device that is produced in 200 pieces a year at 40 $ each does not sound like a good business to me either.

[Bjarne Joergensen]

Hi all

Thanks for all the help answers. The project has been canceled, and I hope they never start it again

Regards Bjarne

[RalcoBe]

Because with the USB interface in your computer you are possibly not even halfway done. You need the driver too. Maybe the device installs itself as USB-COMM device which modern computers will install as virtual RS-232. But I'm really not sure USB was that major and far along when Windows 98 was released so even if the device is a USB-COMM class device the Windows 98 computer may not recognize and install it as Windows serial port device.

If it is not an USB-COMM class device then you would need the according system drivers for Windows 98 (.vxd which are different than the drivers needed for NT based Windows systems such as 2000, XP and newer) and then also create a Modula2 module to access that driver.

But manufacturing a device that is produced in 200 pieces a year at 40 $ each does not sound like a good business to me either.

Sorry, I don't understand anything of it, because I dont' have the right knowledge level.

I just plugged an PCMCIA-USB card in an old win 95 Laptop, so I could share my pictures on an usb stick.

Later on, I did that with a PCI-USB card on a win2000 desktop. Both worked directly, after installing the driver from CD

I understood he just wanted usb on an old PC, no?

[Rolf Kalbermatter]

Sorry, I don't understand anything of it, because I dont' have the right knowledge level.

I just plugged an PCMCIA-USB card in an old win 95 Laptop, so I could share my pictures on an usb stick.

Later on, I did that with a PCI-USB card on a win2000 desktop. Both worked directly, after installing the driver from CD

I understood he just wanted usb on an old PC, no?

Yes, and your PCMCIA-USB comes with drivers that install a raw USB driver in the system (because Windows 95 certainly didn't have USB support on board, it was an addition to the Win95 OEM SR2 that was rather unstandardized). Raw USB is just that, raw. many different USB devices have many different requirements and therefore there exist many different USB device classes, such as mass storage devices, human interface devices, still image capture, printers, serial communication devices etc. Each of them has a different protocol on top of the USB bus and therefore needs different drivers to allow Windows or any OS to do something with them.

Your PCMCIA driver CD likely will install a USB mass storage device driver that makes such devices available to Windows as volumes. It most likely also comes with a human interface device driver, that allows mice and keyboards to be recognized by Windows. It may not come with an USB communication device driver, which would be needed to make a USB COMM class device appear as an additional RS-232 port in your computer. And it will most likely not come with more specialized drivers such as still image class devices or printers or network devices.

All that said it will be very difficult nowadays to find a PCMCIA-USB interface and even more difficult to find one that still supports Windows 98 or even worse Windows 95 since Windows 95 had no USB support in any of its standard releases.

[RalcoBe]

If I understand right, the pcmcia-usb on 95/98 only will support the most mainstream things.

Is it then so, that WinXp also does only this, but is more upgradable? Or comes it by default with everything?

Thanks for the explanation, kudo is sent.

.

[Rolf Kalbermatter]

If I understand right, the pcmcia-usb on 95/98 only will support the most mainstream things.

Is it then so, that WinXp also does only this, but is more upgradable? Or comes it by default with everything?

Thanks for the explanation, kudo is sent.

.

WinXP has a lot more support for USB devices on board. First it comes with drivers for most USB controller chips out there. Second it supports at least HID, COMM, Still Image, PTP, Mass Storage and Printer USB class devices out of the box. Does it come with everything? Of course not because USB allows to define new classes as any manufacturer wishes and if you register them with the USB consortium they are even official standards eventhough nobody but you may using them.