>>I have not idea about other issues but there isn't any trouble about RS232 with VFP. I developed POS and Restaurant POS applications with VFP. These applications work with USB devices same time RS232 devices (displays, scales...).
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>Hi Metin.
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>The trouble is not with the stuff controled by the RS232, it's with the interfaces. I've had a lot of adapters not working.
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>Until not so long ago I've had no broadband connection, so I've used to use a old fashined ISDN interface to go into the net. This interface was using a RS232. I have some other stuff too.
>The comps I own have no RS 232 onboard for more the a decade now. So I use USB devices. More of half of them are simply not working with some / all combinations. of app / comp / device.
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>Just my observations
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>Lutz

I do have VFP programs that communicate with hardware via RS232 -- including USB-to-serial adaptors as well as through Winmodem and USB modems. Initially ran into problems because driver software wasn't getting enough timeslice to service the port -- this was resolved by making sure that I perform DOEVENT prior to most API calls (to make sure driver got a chance to update info prior to the program reading information from it). Perhaps not pretty, and did open things up for other "quirks" -- though it got the job done. As previous poster suggested, VFP is probably not the right tool for the job (given the description you give).