© National Instruments
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5-1
5
Counters
The cDAQ chassis has four general-purpose 32-bit counter/timers and one frequency generator.
The general-purpose counter/timers can be used for many measurement and pulse generation
applications. Figure 5-1 shows the cDAQ chassis Counter 0 and the frequency generator. All
four counters on the cDAQ chassis are identical.
Figure 5-1.
Chassis Counter 0 and Frequency Generator
Counters have eight input signals, although in most applications only a few inputs are used.
For information about connecting counter signals, refer to the
section.
Each counter has a FIFO that can be used for buffered acquisition and generation. Each counter
also contains an embedded counter (Embedded Ctr
n
) for use in what are traditionally
two-counter measurements and generations. The embedded counters cannot be programmed
independent of the main counter; signals from the embedded counters are not routable.
Co
u
nter 0
Co
u
nter 0
S
o
u
rce (Co
u
nter 0 Time
bas
e)
Co
u
nter 0 A
u
x
Co
u
nter 0 HW Arm
Co
u
nter 0 A
Co
u
nter 0 B (Co
u
nter 0 Up_Down)
Co
u
nter 0 Z
Co
u
nter 0 G
a
te
Co
u
nter 0 Intern
a
l O
u
tp
u
t
Co
u
nter 0 TC
Inp
u
t
S
election M
u
xe
s
Fre
qu
ency Gener
a
tor
Fre
qu
ency O
u
tp
u
t Time
bas
e
Fre
q
O
u
t
Inp
u
t
S
election M
u
xe
s
Em
b
edded Ctr0
FIFO
Co
u
nter 0
Sa
mple Clock