serial port usb conflict

[DieselPower]

I communicate with a serial device using a PCI Express board that has four ports on it, 4-7.    I've just added two more Compact DAQ chassis to my system for a total of three.  Now I am getting some conflict between the two.  I lose connection to Compact DAQ chassis and I get junk messages on my serial port.  Any idea as to what the problem might be?  I've had no other trouble with these serial cards or the Compact DAQ hardware in any of my applications.

Thanks.

[The_Red_Barron]

Howdy Michael!

Can you give anymore details regarding the conflict you are experiencing between the devices?  Do you receive any error messages which give additional information?  Is it possible that the device aliases are getting mixed up?

Also, what is the model of the PCIe serial card, the cDAQ chassis, and the modules in the chassis?

Regards,

[DieselPower]

Fortunately or unfortunately, I am unable to reproduce the error.  I will get back to you if it happens again.

[The_Red_Barron]

I'm going to call that one "fortunately" ...fingers crossed that it never happens again.