National Instruments 320174B-01 user manual - page 7

Contents
© National Instruments Corporation vii Lab-NB User Manual
Programming Considerations.........................................................................................4-35
Register Programming Considerations..............................................................4-35
Initializing the Lab-NB Board...........................................................................4-35
Programming the Analog Input Circuitry..........................................................4-36
Analog Input Circuitry Programming Sequence....................................4-36
A/D FIFO Output Binary Modes...........................................................4-38
Clearing the Analog Input Circuitry......................................................4-39
Programming Multiple A/D Conversions on a Single Input Channel...............4-39
Programming in Controlled Acquisition Mode.....................................4-40
Programming in Freerun Acquisition Mode..........................................4-43
External Timing Considerations for Multiple A/D Conversions.......................4-45
Using the EXTTRIG Signal to Initiate a Multiple A/D Conversion
DAQ Operation (Posttrigger Mode)......................................................4-45
Using the EXTTRIG Signal to Terminate a Multiple A/D
Conversion DAQ Operation (Pretrigger Mode).....................................4-46
Using the EXTCONV* Signal to Initiate A/D Conversions..................4-46
Programming Multiple A/D Conversions Using External Timing....................4-46
Programming in Controlled Acquisition Mode.....................................4-46
Posttrigger Mode........................................................................4-46
Pretrigger Mode.........................................................................4-49
Programming in Freerun Acquisition Mode..........................................4-51
Posttrigger Mode........................................................................4-51
Pretrigger Mode.........................................................................4-51
Programming Multiple A/D Conversions with Channel Scanning....................4-51
Interrupt Programming for the Analog Input Circuitry.....................................4-52
Programming the Analog Output Circuitry.......................................................4-52
Interrupt Programming for the Analog Output Circuitry...................................4-54
Programming the Digital I/O Circuitry..............................................................4-55
82C55A Modes of Operation.................................................................4-55
Mode 0–Basic I/O......................................................................4-56
Mode 1–Strobed I/O...................................................................4-56
Mode 2–Bidirectional Bus.........................................................4-56
Single Bit Set/Reset Feature......................................................4-56
Register Descriptions and Programming Examples...............................4-57
Mode 0 Control Words..............................................................4-58
Mode 0 Programming Examples................................................4-58
Mode 1 Strobed Input Control Words........................................4-59
Mode 1 Input Programming Example........................................4-61
Mode 1 Strobed Output Control Words.....................................4-61
Mode 1 Output Programming Example.....................................4-63
Mode 2 Control Words..............................................................4-63
Mode 2 Programming Example.................................................4-65
Single Bit Set/Reset Control Words...........................................4-65
Interrupt Programming for the Digital I/O Circuitry.........................................4-65