Chapter 4
General-Purpose Counter/Timer
©
National Instruments Corporation
4-7
DAQ-STC Technical Reference Manual
Figure 4-7 shows a single-period measurement where the period of G_GATE is five
G_SOURCE rising edges.
Figure 4-7.
Single-Period Measurement
4.4.2.2 Single-Pulsewidth Measurement
In single-pulsewidth measurement, the counter uses G_SOURCE to measure the pulsewidth
of the signal present on the G_GATE input. The counter counts the number of rising edges
that occur on G_SOURCE while the G_GATE signal remains in an active state. At the
completion of the pulsewidth interval for G_GATE, the HW save register latches the counter
value for software read. Figure 4-8 shows a single-pulsewidth measurement where the
pulsewidth of G_GATE is five G_SOURCE rising edges.
Figure 4-8.
Single-Pulsewidth Measurement
4.4.2.3 Buffered Period Measurement
Buffered period measurement is similar to single-period measurement, except that
measurements are taken for multiple periods. The counter uses G_SOURCE to measure the
time interval between two active edges of the signal present on the G_GATE input, counting
the number of rising edges that occur on G_SOURCE between each pair of active edges of
G_GATE. At the completion of each period interval for G_GATE, the HW save register
G_SOURCE
G_GATE
Counter Value
HW Save Register
1
0
3
5
4
5
2
G_SOURCE
G_GATE
Counter Value
HW Save Register
1
0
3
5
4
5
2
