should i buy a FPGA or a DSP?

[maggie_ok]

Hello, I want to configure a FEEDBACK control system using the PXI real time system. However, I am confused which module should I choose, the FPGA or the DSP for PI control and digital signal processing.

There are 4 feedback loops in the system. I want one of them to run at a speed of higher than 100kHz, the other three at a speed around 20kHz. Will the NI PXI-7853R be OK? Or should I choose the DSP module like NI SPEEDY-33?

Thanks a lot.

[N.Urakawa]

Hi maggie ok

Thanks for the post.

Feedback control can be done with both FPGA and DSP module.  It all depends on what you are opporating from the feedback control.  With FPGA module, the number of functions are limited compared to DSP module.  Therefore, if you are doing some simple calculation like addition, subtraction, multiplication and so on, I would recommend FPGA module since the loop goes at the fastest rate.  However, if you are planning to do a little more complicated task than addition like filtering and fft, I would recommend DSP module.

Hope this helped

Noboru Urakawa