Hybrid Acquisition DMA + DAQmx on CRIO904X or 905X

[Michele__]

Hello LabVIEW community,

I have this topic to understand

I have crio that support DAQmx acquisition, and I want to manage acquisition of data by this way

1)  fixed crio module channel acquired using DMA FPGA (for example voltage, current, torque, position channels on slot 1 and slot 2 of chassis) always included in acquitions, so I don't need to change FPGA code

2)  list of variable channels acquired using DAQmx (temperatures, flow meters, force sensors). this could be helpful because to the final user, he can configure hardware for different tests and also the software,  and to me, i will have data from DAQmx in physical unit without converting signal of TCs, resistors on RT side

i'm able to manage acquisition from DMA and DAQmx in the same loop, but i need to understand how to synch data to use the same timestamp (t0 that comes from DAQmx)

can you help me? now i'm reading data of variable channels using ScanEngine Mode, and then write single value in FPGA control. but i would like to improve this way to do

thank you for the support!

best regards

[ZYOng]

If you want both ease of configuration and synchronization, DAQmx mode is the way to go.

See Signal-based Synchronization of Analog Input C Series Modules with NI-DAQmx in LabVIEW

[Michele__]

Hi ZYOng,

reading info on NI forum I have found that I could synch NI FPGA time using FPGA Timekeeper lib

FPGA Timekeeper 1.1b0.zip - NI Community

because my hardware setup is one single chassis, with no NI timing synch module. 

Is timekeeper the way that I can use to synch time between fpga target and DAQmx driver?

best regards

Michele

[ZYOng]

Why would you want to sync FPGA timing? Are you using any modules in FPGA?

[Michele__]

Hi ZYOng,

yes, I have crio modules under FPGA, and other modules configured as DAQmx

This post is what I need, to synch data from FPGA and DAQmx

Solved: FPGA and DAQ card synchronization - NI Community

thank you!