USB to COM issues

DEARINGMR

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Jul 6, 2015
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This company runs a very small spice blending business and use a 100lb platform scale hooked up to a laptop running some weight management software.

The scale itself was shipped with a COM serial port but with some ingenuity the former tech guy spliced in a USB male end and made it work for 4-5 years with this old laptop.

Laptop HD died so i'm trying to hook up a new device. We have a few Panasonic Toughbooks laying around (Toughbook FZ-G1 Tablet running Windows 7) but they only have the single USB port.

The owner remembers needing to use a USB to serial adapter driver to get the computer to recognize the scale as a COM instead of an 'Unknown USB Device'.

As of right now the scale will only recognize under the USB controllers, and not under COM. The software they use only recognizes COM.

In a perfect world, we could have just bought a SERIAL to USB adapter and used the given Driver to make it work. Now I have a spliced scale cord to USB- but shouldn't the driver still work?

Ive tried 3x different companys adapter drivers and I can't seem to get them to work. All three said successfully installed but don't make any difference in how the scale is treated when It gets plugged in. (I have uninstalled/deleted the old drivers before trying a new one)

I'm not at all sure how USB/COM ports work, I just need this USB to be recognized as a COM port so I can rename/reclass it as COM 1 so the software can use it.

Any ideas at all? My Googlefu only brings up issues where people can already see their device listed under COM.
 
Solution
This sounds similar to a situation I've had to deal with. The root of the problem is that modern versions of Windows (at least from XP and up) do not allow software to take direct control of an I/O port. ALL such ports are managed by Windows. On the other hand, much older software was accustomed to doing just that. They ignored Windows and just tried to manipulate the ports directly. Under current Windows, that won't work.

The solution is to use a Windows networking command called NET USE in a batch file. It is really a way to tell Windows to re-route I/O from one port to another on the network. So to use it you need to have a minimal "network" working. As long as your laptop has a network port and its driver is installed, this will...
This sounds similar to a situation I've had to deal with. The root of the problem is that modern versions of Windows (at least from XP and up) do not allow software to take direct control of an I/O port. ALL such ports are managed by Windows. On the other hand, much older software was accustomed to doing just that. They ignored Windows and just tried to manipulate the ports directly. Under current Windows, that won't work.

The solution is to use a Windows networking command called NET USE in a batch file. It is really a way to tell Windows to re-route I/O from one port to another on the network. So to use it you need to have a minimal "network" working. As long as your laptop has a network port and its driver is installed, this will suffice. You won't necessarily need that port to be connected to a working network. Look up details of how to use the NET USE command on the Microsoft site. It has several forms to do several jobs. The key one for this is a form that tells it that any communications issued by software run under Windows (even old software) should be re-directed to a different communication port on the computer. In your case, you want traffic sent out by the old software to the COM port to be re-directed to an actual USB port that is already established (under Windows) and working to communicate with the weight scale. That way the old software that does not know how to use USB ports CAN use the connection to the scale.

In my case, instead of simply clicking on the old software's icon to start it, I wrote a small .BAT file, and I click on its icon. Within that file, it does four things, all of them using various syntaxes of NET USE:
1. Deletes all existing NET USE re-direction commands, just in case some previous operation left a re-direction hanging around.
2. Directs all activity for the COM1 port to use a designated specific USB port until further notice.
3. Starts up the old software.
4. (Batch file arrives here when the old software is closed) Deletes all existing NET USE re-direction commands so there are none left to cause problems to other applications, then quits.

I'm using this with very old software from the 1990's designed for use under DOS. It did work fine that way, AND it worked OK under Windows up to Win 98 SE. It just did not work under Win XP. The software suppliers gave me this info about NET USE, and the batch file I use for this works perfectly. I even had two additional glitches to deal with that you do not have, OP. Don't worry about these, I'll just mention them for info and to illustrate that there are ways to do these things .... (a) My old printer in use is connected to the COM1 port, but you can't use NET USE to re-direct traffic from a COM port to itself. So I had to re-configure the old software to believe the printer was on the LPT1 parallel port, and set the batch file to re-direct that to the COM1 port. (b) the setup was a retail store point of sale system that had NO network connection at all, not even a network card in the computer. I could have installed a network card and driver to solve that. But instead I used a trick supplied by that software company. One of the files included in Windows but not normally used is a service diagnostic tool that, when run, creates a minimal virtual "network" that can respond to many network commands like NET USE so that they function properly even without a network. Placing that in one of the system start-up files gave me the virtual network that the batch file could use for printer re-direction. These days, however, since that computer now does have a network card and connection, that last trick is not needed.
 
Solution

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