I wrote a vb6 program (using mscomm32.ocx control) that acts like a generic version of hyperterminal: it looks for any data coming in on the selected serial port and displays this on the screen, and it has a spot where you can type in text and send it out the serial port. When I run this on win 7 64 bit, can send data but when receive a character I get “Error reading comm device”.
This program works fine with pluggable usb serial converter on win 7 32 bit, and works with another manufacturer converter on win 7 64 bit, which proves to me that the mscomm32 control on win 7 64 bit is not the problem.
Hi Jeff,
Thank you for posting about your USB serial adapter. I’m sorry you are having troubles with it.
We have seen issues with mscomm32 in vb6 with Windows 64-bit computers, and it seems to be a known error at Microsoft. There is a KB article about it here:
http://support.microsoft.com/kb/318784
Their suggested solution is to contact the manufacturer for a new driver, but it looks like you have the latest installed.
Maybe there is a workaround in the meantime?
Also, we have seen some issues with the driver installation dated 2/5/13 that actually installed a driver earlier than expected, and there is an updated driver package currently available that ensures the latest versions are actually installed. Could you try uninstalling the current driver and installing this one? The link is:
http://plugable.com/drivers/prolific
Thank you,
David
Plugable Support