National Instruments NI cDAQ-9181 - External or Internal Source Less than 20 Mhz

5-40 | ni.com
Chapter 5 Counters
External or Internal Source Less than 20 MHz
With an external or internal source less than 20 MHz, the module generates a delayed Source
signal by delaying the Source signal by several nanoseconds. The chassis synchronizes signals
on the rising edge of the delayed Source signal, and counts on the following rising edge of the
source, as shown in Figure 5-39.
Figure 5-39. External or Internal Source Less than 20 MHz
Source
Delayed Source
Synchronize
Count