I'm wondering if you fixed your problem yet or not.

I had a similar issue and what I discovered what the serial cable would work with a micro controller based engine tuning device on my laptop, but it would not work on my desktop........I believe someone prior had the same issue.

Please let me know if you figured this out yet or not.

-Jimmy Kelley
rs232-converters.com

There is not a problem per se with any of the Oak Micros devices. The problems seem to occur with the USB to RS232 converter cables.

If they don't supply the DTR line at all then they won't work. This is true of some "cheaper" converters.

The USB port must be configured correctly for the converter to work correctly. Tony's post on this subject gives all of the details.

As a side note, Oak Micros is now producing devices with a builtin FTDI USB to RS232 converter. See the ZX-328nu, ZX-24nu, ZX-24pu and om328p devices. The om644p will be available soon also with USB support.

-- Mike