USB to Serial converter problems

I am trying to use a USB to serial converter to load a program onto a RCM3110 core without luck.
The USB-Serial converter drivers have been loaded and confirmed working.
I am using RFU V 3.02. I’m using Vista but that doesn’t seem to matter, it’s been tested with everything from Win98 and later with the same lack of results. It just says “No Rabbit detected”
I can load the program through a standard serial port.
The USB-Serial converter does work to send and recieve data after the program has been loaded so I know it’s not the device that the core is attached to.
I’ve tested every combination of enable processor detection, Disable Baud negotiation, stop bits and enable USB to Serial Converter that I can.
I doubt it matters but the standard serial port is on Com6 and the USB to Serial converter is on COM 3…yes, I’ve changed the setting for that too.
The speed for debug rate and max download speed doesn’t matter either.

Any ideas ??? Thanks.

You might want to take a look at Tech note TN258 - USB to RS-232 Converter Cables User�s Guide and also TN257 � Running Dynamic C� With Windows Vista�
both located at

I hope this helps

I need to make this work for RFU v 3.02 as that is distributed to my customers. My customers don’t have Dynamic C or a fallback standard serial port.

No luck with the FTDI drivers.

I am not using the specific USB to Serial converter mentioned in the white paper but I have confirmed that the one I’m using works with my device for sending and receiving data. I see no reason why it wouldn’t work for upgrading the BIN file.

It only doesn’t work for updating the program in the RCM itself.

My customers are getting rather angry at not being able to update their program and I’m taking the heat.

Any ideas would be most welcome.


Unfortunately, we cannot guarantee any USB cables that we do not recommend. If you have a dual core processor on your laptop or PC you must run the affinity app that is mentioned in the Tech note.

If this still fails after following the recommendations in both Tech Notes, please send your request to and we will investigate further.

If I run the affinity and re-compile as recommened, will that work for my customers who do not have Dynamic C, only RFU ?

Logically, my guess is that it would not.

It should work for both RFU and Dynamic C.


Did you get it to work? I’ve been trying to get a USB chip to work - I need to change my products interface from serial to USB - so I added a USB chip - it works using RFU but not reliably. It works better on an XP based machine – works very rarely on a Vista machine. ALso I can’t get DC9.62 to work reliably - I’m forced to keep my old XP machine running 7.25 (which works 100% all the time).