NI 9469 - using external signal as master timebase for other Delta Sigma Modules in cRio chassis

[Cefa]

Hi,

Im looking for any solution how to route external clock signal for timebase of Delta Sigma modules (9234, 9237, etc...) on cRio. With cRio platform It is not generally possible (unlike CompactDAQ platform) to route external clock signal for delta sigma modules timebase. Only solution is to export internal timebase from another delta sigma module in the same chassis and use it as master in another module. 

Now I have found NI 9469 synchronization module. Its designed to synchronize 2 or more cRio chassis together and in Slave mode it can import external clock thru Input0 / Pin3 - but this is mainly intended to receive clock signal from another NI 9469 module. 

Do you have any idea if its is possible to use as input for external clock signal (for example 12.8 Mhz from GPS precise clock)? Have anyone tried to use it this way? 

Thank you for any answer 🙂

[ZYOng]

What is your cRIO model?

cRIO-904x/905x support DAQmx mode and work like cDAQ.

[Cefa]

Hi ZYOng,

thank you for info. I have cRIO 9035 (more than one, so I can not purchase any other one). 

Im not familiar with cRIO cDAQ mode and it new information for me. But I prefer to keep acces to FPGA direct programing mode and Im not sure if switching to cDAQ mode will do this.

Is it similar to Scan mode where FPGA is running on fixed bitfile and cannot be modified?

Its interesting there is direct acces to route clock signal to Delta sigma oversample clock via digital input modules or PFI but not same option on cRIO 🙂 . I believe there must be similar FPGA running in cDAQ chassis. 

But back to original question. Do you know if module NI 9469 can be used this way and route external clock to delta sigma master Timebase? I can purchase one but I want to be sure before spending budget on it.

Thank you

[Souhe]

Hi Cefa,

Theoretically, this is not possible on cRIO, according to the cRIO development guide (guide.pdf). C Series modules that use Delta-Sigma converters cannot be synchronized to an external clock,  they can only be synchronized among each other. Your proposed solution has not been officially tested, so I recommend contacting your NI advisor for proper guidance.

Souha