Hello,
By default when you use the nidaqmxconfig utility to install/configure your DAQmx devices, they will be named "DevX," where X is the decided based on the order of installation. If you were going to be installing multiple PCI-6221s then they would be named Dev1, Dev2, Dev3, etc. There are a couple good developer zone articles that address this issue. Here is one that is an NI-DAQmx for Linux FAQ and here is one about using nidaqmxconfig.
Chris
