CompactDAQ chassis and X Series devices have onboard counters you can
configure and use similarly to counter module channels. An onboard counter looks
like a module in FlexLogger, but it is not a module and functions differently from a counter
module, such as the NI 9361.
When configuring and using onboard counters, keep in mind the following functionality:
- cDAQ chassis and X Series devices connect differently—You can use the available digital
lines to connect to the onboard counter of X Series devices. To connect to the onboard
counter of a cDAQ chassis, you must connect a digital device to the chassis. For more
information about supported digital modules, refer to Digital I/O Considerations for
C Series Devices in NI-DAQmx Help matching your driver version.
- You must specify the input terminal—You may have multiple options to use as the input
terminal. You must specify which digital line you want to use as the input terminal.
- Onboard counters cannot create their own internal sample clock—Onboard counters cannot
divide down their timebase to create an internal sample clock. FlexLogger uses the
Frequency Output (FREQ OUT) signal to supply the clock source.
- Onboard counters have fixed supported sample rates—Sample rates cannot synchronize with
anything else on the board and use a fixed number of sample rates based on the Frequency
Output signal. The signal uses the 20 MHz, 10 MHz (20 MHz divided by 2), or 100 kHz
Timebase, which you can divide by an integer from 1 to 16.
You can find more information about onboard counters and the Frequency Output signal in the
cDAQ chassis and X Series device user manuals under