National Instruments Welding System 321645c-01 사용자 설명서
Chapter 2
Function Reference — CTR_EvRead
NI-DAQ FRM for PC Compatibles
2-94
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National Instruments Corporation
CTR_EvRead
Format
status = CTR_EvRead (deviceNumber, ctr, overflow, count)
Purpose
Reads the current counter total without disturbing the counting process and returns the count
and overflow conditions.
and overflow conditions.
Parameters
Input
Output
Parameter Discussion
ctr is the counter number.
Range:
1, 2, or 5 for an MIO device except the E Series devices.
1 through 10 for a PC-TIO-10.
1 through 10 for a PC-TIO-10.
overflow returns the overflow state of the counter. A counter overflows if it counts up to
65,535 and rolls over to zero on the next count. If overflow = 0, no overflow has occurred. If
overflow = 1, an overflow occurred. See the
65,535 and rolls over to zero on the next count. If overflow = 0, no overflow has occurred. If
overflow = 1, an overflow occurred. See the
section later in this function.
count returns the current total of the specified counter. count can be between zero and 65,535.
count represents the number of edges (either falling or rising edges, not both) that have
occurred since the counter started counting.
count represents the number of edges (either falling or rising edges, not both) that have
occurred since the counter started counting.
Note
C Programmers—overflow and count are pass-by-reference parameters.
Name
Type
Description
deviceNumber
i16
assigned by configuration utility
ctr
i16
counter number
Name
Type
Description
overflow
i16
overflow state of the counter
count
u16
current total of the specified counter