National Instruments 321645c-01 User Manual

Chapter 2

Function Reference — CTR_EvCount

©

 National Instruments Corporation

2-93

NI-DAQ FRM for PC Compatibles

10:

SOURCE5 used as timebase if 1 

≤

 ctr 

≤

 5 or SOURCE 10 used as timebase 

if 6

≤

ctr 

≤

 10.

11:

GATE 1 used as timebase if 1 

≤

 ctr 

≤

 5 or GATE6 used as timebase 

if 6

≤

≤

10.

12:

GATE 2 used as timebase if 1 

≤

 ctr 

≤

 5 or GATE7 used as timebase 

if 6

≤

≤

10.

13:

GATE 3 used as timebase if 1 

≤

 ctr 

≤

 5 or GATE8 used as timebase 

if 6

≤

≤

10.

14:

GATE 4 used as timebase if 1 

≤

 ctr 

≤

 5 or GATE9 used as timebase 

if 6

≤

≤

10.

15:

GATE 5 used as timebase if 1 

≤

 ctr 

≤

 5 or GATE10 used as timebase 

if 6

≤

≤

10.

Set timebase to zero to concatenate counters. Set timebase to 1 through 5 for the counter to 
count one of the five available internal signals. Set timebase to 6 through 15 (except 10 for 
the PC-TIO-10) to provide an external signal to a counter. This external signal is then the 
signal NI-DAQ counts for event counting. 

cont indicates whether counting continues after the counter reaches 65,535 and rolls over to 
zero. cont can be either zero or 1. If cont = 0, event counting stops when the counter reaches 
65,535 and rolls over, in which case an overflow condition is registered. If cont = 1,  event 
counting continues when the counter rolls over and no overflow condition is registered. 
cont = 1 is useful when more than one counter is concatenated for event counting.

CTR_EvCount

 configures the specified counter for an event-counting operation. The function 

configures the counter to count up from zero and to use the gating mode, edge mode, output 
type, and polarity as specified by the 

CTR_Config

 call.

Applications for 

CTR_EvCount

 are discussed in Event-Counting Applications in Chapter 3, 

Software Overview, of the NI-DAQ User Manual for PC Compatibles.