Hi all. Hope someone can help!

I have an app that connects to a NetCom 413 RS232/422/485 - Ethernet converter. In fact several converters, all the same type. The converter uses virtual com ports addressed to the IP of the converter to relay traffic.

Each converter has connected, a printer (RS232), bar code scanner (RS232) and an HMI display (RS422).

Everything works fine for some time, then the PC appears to drop the serial line connected for the scanner, the scanner scans, the converter lights flicker to say it's sending data but nothing is recevied at the PC.

The application doesn't hang, all the other lines continue to work ok, but this is happening randomly on all connected converters. I cannot believe all 4 converters have a fault, so I can only point to the virtual com port drivers, which are up to date, or a problem with the VB2005 serial port control.

Does anyone have any ideas?
Cheers,
Tull.