NI 9205 DAQ with incremental Encoder

[chgaga]

Hi everybody, I am pretty new to DAQ and a little stuck at the Moment. Maybe somebody can point me in the right direction.

What I basically want to do is to run an asynchronous measurement of a displacement sensor (analog) and every time when an incremental encoder (digital Trigger) sends a Signal, I want to record one sample. Therefore, I have a 9205 modul combined with a cDAQ-9184 chassis. The external trigger source is linked with PFI0.

Now, starting the acquisition with the trigger and acquiring continous data is not a problem. However, my main problem is, at least to my understanding, that I do not have a counter on this module, with which I could tell my program to store one sample of data in a variable. With the current trigger I only can start the measurement.

At the moment I am using Matlab (session based interface) as software, because it is the only program I am familiar with and I it is currently available. Maybe this is done easily with LV or maybe it is not possible with Matlab or the module at all.

Anyway, thanks in advance and any advice would be more than welcome. Cheers   

[Duffy2007]

Hello chgaga,

i do not have Matlab. What you can try is to connect one line from the encoder to the PFI1 of the 9184, if it is TTL compatible. Normally the timing was done with the internal sample clock, change this from onboard timing to PFI1 in LabVIEW the name of the function is DAQmx Timing, or the property has the name "Sample Clock : Timebase : Source Property", then with every increment from the encoder a sample will be acquired.