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Chapter 2 Function Reference — ICTR_Setup
NI-DAQ FRM for PC Compatibles 2-254
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National Instruments Corporation
See the 8253 Programmable Interval Timer data sheet in your DAQCard-500/700 or Lab and
1200 Series user manual for a detailed description of these modes and the associated timing
diagrams.
count is the period from one output pulse to the next.
Range for modes 0, 1, 4 and 5:
0 through 65,535 in binary counter operation.
0 through 9,999 in BCD counter operation.
Range for modes 2 and 3:
2 through 65,535 and 0 in binary counter operation.
2 through 9,999 and 0 in BCD counter operation.
Note Zero is equivalent to 65,536 in binary counter operation and 10,000 in BCD
counter operation.
Note BASIC Programmers—NI-DAQ passes count as a 16-bit unsigned number. In
BASIC, integer variables are represented by a 16-bit two’s complement system.
Thus, count values greater than 32,767 must be passed as negative numbers. One
way to obtain the count value to be passed is to assign the required number
between zero and 65,535 to a long variable and then obtain count as shown below:
count% = lcount& - 65,536
binBcd controls whether the counter operates as a 16-bit binary counter or as a 4-decade
binary-coded decimal (BCD) counter.
0: 4-decade BCD counter.
1: 16-bit binary counter.