Chapter 4
General-Purpose Counter/Timer
DAQ-STC Technical Reference Manual
4-76
©
National Instruments Corporation
4.8.11.6 Single-Period Measurement
To use this function, set G_CONTROL conditioning to edge gating and program the counter
to count once. The rising edge of G_GATE is synchronized by the falling edge of
G_SOURCE to generate a G_CONTROL pulse. The counter increments on every
G_SOURCE rising edge following the G_CONTROL pulse. On the second G_CONTROL
pulse, the counter disarms. The HW save register switches to transparent mode on the rising
edge of G_GATE and returns to latched mode on the next G_SOURCE falling edge.
Figure 4-37 shows an example of a single-period measurement where the period of G_GATE
is five G_SOURCE rising edges. The dotted line indicates where the ARM occurs and the
arrows indicate where the gate interrupt is generated.
Figure 4-37.
Single-Period Measurement
Counter Value
G_SOURCE
G_GATE
G_CONTROL
HW Save
HW Save Register
0
1
2
3
4
5
0
5