National Instruments NI USB-621x manual 11

	Contents
Chapter 11
Isolation and Digital Isolators
Digital Isolation .............................................................................................................	11-2
Benefits of an Isolated DAQ Device .............................................................................	11-2
Reducing Common-Mode Noise ...................................................................................	11-2
Creating an AC Return Path ............................................................................	11-3
Isolated Systems................................................................................	11-3
Non-Isolated Systems .......................................................................	11-3
Chapter 12
Digital Routing and Clock Generation
80 MHz Timebase..........................................................................................................	12-1
20 MHz Timebase..........................................................................................................	12-1
100 kHz Timebase .........................................................................................................	12-2
Chapter 13
Bus Interface
USB Signal Streams.......................................................................................................	13-1
Data Transfer Methods ..................................................................................................	13-1
USB Signal Stream..........................................................................................	13-1
Programmed I/O ..............................................................................................	13-2
Changing Data Transfer Methods ...................................................................	13-2
Chapter 14
Triggering
Triggering with a Digital Source ...................................................................................	14-1
Appendix A
Device-Specific Information
USB-6210 ......................................................................................................................	A-1
USB-6211/6215 .............................................................................................................	A-4
USB 6218.......................................................................................................................	A-7

© National Instruments Corporation xi NI USB-621x User Manual