National Instruments Data Acquisition Device NI USB-621x - Page 8

Contents
NI USB-621x User Manual viii ni.com
Chapter 6
Digital I/O
Digital I/O on USB-6210/6211/6215/6218 Devices ..................................................... 6-1
Static DIO on USB-6210/6211/6215/6218 Devices ....................................... 6-2
I/O Protection on USB-6210/6211/6215/6218 Devices.................................. 6-2
Increasing Current Drive on USB-6210/6211/6215/6218 Devices ................ 6-3
Connecting Digital I/O Signals on USB-6210/6211/6215/6218 Devices....... 6-3
Getting Started with DIO Applications in Software on
USB-6210/6211/6215/6218 Devices ........................................................... 6-4
Digital I/O on USB-6212/6216 Devices........................................................................ 6-4
Static DIO on USB-6212/6216 Devices ......................................................... 6-5
I/O Protection on USB-6212/6216 Devices.................................................... 6-5
Programmable Power-Up States on USB-6212/6216 Devices ....................... 6-6
Increasing Current Drive on USB-6212/6216 Devices................................... 6-6
Connecting Digital I/O Signals on USB-6212/6216 Devices ......................... 6-6
Getting Started with DIO Applications in Software on
USB-6212/6216 Devices.............................................................................. 6-7
Chapter 7
PFI
Using PFI Terminals as Timing Input Signals .............................................................. 7-2
Exporting Timing Output Signals Using PFI Terminals............................................... 7-3
Using PFI Terminals as Static Digital I/Os ................................................................... 7-3
Connecting PFI Input Signals........................................................................................ 7-4
PFI Filters ...................................................................................................................... 7-4
I/O Protection ................................................................................................................ 7-6
Programmable Power-Up States.................................................................................... 7-6
Chapter 8
Counters
Counter Input Applications ........................................................................................... 8-2
Counting Edges ............................................................................................... 8-2
Single Point (On-Demand) Edge Counting ...................................... 8-2
Buffered (Sample Clock) Edge Counting......................................... 8-3
Controlling the Direction of Counting.............................................. 8-4
Pulse-Width Measurement.............................................................................. 8-4
Single Pulse-Width Measurement .................................................... 8-4
Buffered Pulse-Width Measurement ................................................ 8-5
Period Measurement ....................................................................................... 8-6
Single Period Measurement.............................................................. 8-6
Buffered Period Measurement.......................................................... 8-7