National Instruments NI USB-621x - Manual (Page 11)

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