Справочник Пользователя для National Instruments 321645c-01
Chapter 2
Function Reference — GPCTR_Config_Buffer
©
National Instruments Corporation
2-209
NI-DAQ FRM for PC Compatibles
GPCTR_Config_Buffer
Format
status = GPCTR_Config_Buffer (deviceNumber, gpctrNum, reserved, numPoints, buffer)
Purpose
Assigns a buffer that NI-DAQ will use for a buffered counter operation.
Parameters
Input
Parameter Discussion
The legal range for gpctrNum is given in terms of constants defined in a header file. The
header file you should use depends on the language you are using:
header file you should use depends on the language you are using:
•
C programmers—
NIDAQCNS.H
(
DATAACQ.H
for LabWindows/CVI)
•
BASIC programmers—
NIDAQCNS.INC
(Visual Basic for Windows programmers should
refer to the
section in Chapter 1,
, for more information.)
•
Pascal programmers—
NIDAQCNS.PAS
gpctrNum to indicates which counter to program. Legal values for this parameter are in
Table 2-20.
Table 2-20.
numPoints is the number of data points the buffer can hold. The definition of a data point
depends on the application the counter is used for. Legal range is 2 through 2
depends on the application the counter is used for. Legal range is 2 through 2
32
– 1.
When you use the counter for one of the buffered event counting or buffered time
measurement operations, a data point is a single counted number.
measurement operations, a data point is a single counted number.
buffer is an array of unsigned 32-bit integers.
Name
Type
Description
deviceNumber
i16
assigned by configuration utility
gpctrNum
u32
number of the counter to use
reserved
u32
reserved parameter, must be 0
numPoints
u32
number of data points the buffer can hold
buffer
[u32]
used to hold counts