Frequency and Duty Cycle measurement with NI 9361

[Madottati]

Hello,

in the LabVIEW examples there is a Counter - Read Pulse Duty Cycle and Frequency (Continuous).vi

As in this VI, I want to use the Counter 1D Pulse Freq 1Chan NSamp type reading, so that I get a Cluster with frequency and duty cycle.

I have a NI 9361 module. If I select the physical channel "NI_9361/ctr0" on the front Panel, I get an error -200431:

"Selected physical channel does not support the measurement type required by the virtual channel you are creating."

Can anybody tell me how to measure frequency and duty cycle of a PWM Signal using NI 9361?

[Madottati]

just for the accuracy:

Chassis: NI cDAQ-9184

LabVIEW 2015 SP1 f5

DAQmx 17.1

[Duffy2007]

Hello Madottati

you have to use two counters and wire a bridge between the two inputs. This module do not support combine measurements like semi period and period with frequency measurement. In the datasheet you find the possible options

[Madottati]

Hi,

thanks for your reply. It's no Problem to use two Counter Inputs, the Problem is to configure the two Tasks.

If I run the attached VI, I get an error -200287 : Some or all of the samples requested have not yet been acquired.

Can you help me how to configure it?

[Duffy2007]

Hello Madottati                    

sorry i do not have the hardware at the moment so i can not test

bassed on this kb:

How Many Different Tasks Can Concurrently Run on a CompactDAQ Chassis Gen II?

The NI 9361 only supports a single task. If you need to use multiple counters from the NI 9361, you need to add all the required counters to the same Task.

[opejumeys]

You could also use the same physical channel by remapping the terminal using the DAQmx Channel property node.

by default /ctr0 maps to /PFI0   ....   ctr7 maps to /PFI7