trigger analog input by logic inputs (incremental)

[greg31]

Hi

I would like to trigger analog inputs (4 inputs, 1 sample) at each change of a two inputs incremental counter.

Is there a way to do that with labview?

I use a cDAQ9174 chassis with a NI9361 counter module and a NI9229 analog input module.

Thanks

Gregory

[Jun']

Hi Gregory,

Do you know at what rate/frequency are going to run your 2 incremental counters?

Thanks,

M-Junior

[greg31]

Hi,

I need to acquire only one incremental encoder. A and B are the quadrature outputs of this encoder.

I need to trigger a 1 sample analog acquisition at each rising or falling edge of A or B.

Moreover i need to count and date the edges to compute the absolute position and corresponding instant velocity of the encoder.

The rate should be between 10 000 and 100 000 edges per second.

Regards

Gregory

[Jun']

Hi Gregory,

Unless you are using an FPGA, this does not seem possible to me.

Thanks,

M-Junior

[greg31]

The NI9361 can take the quadrature signals as input and count, it's a specific feature of this card :

http://www.ni.com/pdf/manuals/374646a.pdf

There is no need of real time logic for this

As said in the spec, in a  CompactRio the card can also compute velocity, but I have a compatDAQ...

I want to record  at each edge detected :

count , edge time,  analog acquisition 1 .. analog acquisition 4 ( 4 signals 1 sample )

...

With Labview/DAQmx I don't know how to take the quadrature edges as trigger for the acquisition...

Regards

Gregory