Contents
PC-OPDIO-16 User Manual vi © National Instruments Corporation
Chapter 3
Signal Connections.............................................................................................................3-1
I/O Connectors............................................................................................................... 3-2
Signal Connection Descriptions.........................................................................3-3
Optically Isolated Digital Output ..................................................................................3-4
Output Channels.................................................................................................3-4
Signal Isolation ......................................................................................3-4
Signal Connection Example...................................................................3-5
Increasing Switching Frequency for TTL Loads................................... 3-6
Power-on Condition............................................................................... 3-6
Optically Isolated Digital Input......................................................................................3-6
Input Channels ...................................................................................................3-6
Sensing DC Voltages......................................................................................... 3-7
Sensing AC Voltages......................................................................................... 3-7
Signal Isolation ..................................................................................................3-7
Signal Connection Example...............................................................................3-7
Reducing the Forward Current for 24 V Inputs................................................. 3-8
Power-on Condition........................................................................................... 3-8
Chapter 4Fundamentals of Building Applications with NI-DAQ
Building DOS Applications with NI-DAQ....................................................................4-1
Creating a DOS Application Using Microsoft C............................................... 4-1
Example Programs................................................................................. 4-2
Creating a DOS Application Using Visual Basic ..............................................4-2
Running Your Application Inside the Visual Basic Environment.........4-4
Compiling and Running Your Visual Basic Application from the
DOS Prompt...........................................................................................4-4
Example Programs................................................................................. 4-5
Creating a DOS Application Using Borland Turbo C++ or Borland C++ ........4-5
Example Programs................................................................................. 4-6
Creating a DOS Application Using Borland Turbo Pascal................................4-6
Memory Requirement............................................................................ 4-7
Example Programs................................................................................. 4-7
Building Windows Applications with NI-DAQ.............................................................4-7
The NI-DAQ Libraries.......................................................................................4-8
NI-DAQ Programming Considerations .............................................................4-8
Buffer Allocation ...............................................................................................4-8
Huge (Greater Than 64 KB) Buffer Access...........................................4-9
String Passing.........................................................................................4-9
Parameter Passing.................................................................................. 4-9
Creating a Windows Application Using Borland C++...................................... 4-9
Example Programs................................................................................. 4-10
Special Considerations...........................................................................4-10
Creating a Windows Application Using Microsoft Visual C++........................4-11
Special Considerations...........................................................................4-11
Creating a Windows Application Using Turbo Pascal ......................................4-11
Example Programs................................................................................. 4-12
Special Considerations...........................................................................4-12