Sam,
I never heard about "
zmq block or socket to pass" I will look into those methods.

Something tells me I should go the route to write my own block but I don't know where to start. 
Would you have a link?

Note, I don't want a block of samples to go to my app, what I want is each time the FIR filter spits out a sample I want to process it with my app.

TNX
Pete

On 3/4/2019 4:38 PM, samuel verdon wrote:
Hello, 

You can use a zmq block or socket to pass your data to your app or if you want you can write your own block that pass your data to your app via a callback method.

Sam