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Appendix A
Specifications
©
National Instruments Corporation
A-3
DAQCard-DIO-24 User Manual
Transfer Rates
Transfer rates are a function of the speed with which your program
reads data from or writes data to the card and therefore vary with your
system, software, and application. The following primary factors
control DAQCard-DIO-24 transfer rates:
•
Computer system performance
•
Programming environment (register-level programming or
NI-DAQ)
•
Programming language and code efficiency
•
Execution mode (foreground or background, with background
execution typically using interrupts)
•
Other operations in progress
•
Application
For example, you can obtain higher transfer rates in a handshaking or
data-transfer application, requiring an average rate, than in a pattern
generation, data acquisition, or waveform generation application,
requiring a constant sustainable rate.
Table A-1 shows maximum rates on two computer systems using
register-level programming, with an efficient assembly language or C
program, running in the foreground, with no other operations in
progress. The numbers shown are average, rather than constant
sustainable, rates.
The code used to make the measurements follows the table. The
assembly language code was assembled as inline assembly C code
using Microsoft Optimizing C Compiler, version 8.00. The C code was
compiled using Microsoft Optimizing C Compiler, version 8.00.