Any way to get >20MHz digital out on crio 9082?

[maherhome]

Hi,

We already have a cRIO 9082 and REALLY want to generate a 25 MHz (manchester) signal with it (in order to sync with another device that needs the 25 MHz manchester).  I understand 20 MHz is the highest rate for a dio module.  Are there any tricks or third party solutions that could get us to 25 MHz?

We're starting to think about external circuits; I'm not fluent in phase locked loops (I'm from the software side) but it seems like it would be difficult given the manchester signal.  

Steve

[[dk]]

The 9402 module has a 20 MHz maximum clock rate, which, as you stated, is the fastest rate for a DIO module. However, I have done seen some benchmarking before using a CompactRIO 9082 with a 9402 module that was capable of generating a clock signal with a 30nS period (~33.3 MHz). This was done using a 200 MHz derived top-level clock and the FPGA target cannot use a clock faster than 200 MHz for it's top-level clock. 

Keep in mind that this is by no means official, it was just some random benchmarking that I done before. Just wanted to state this since it is not an official specification of the 9402 at all. Hope this helps though!

[maherhome]

Heck ya that helps! I can't imagine much of a better comment 🙂

I know it's unofficial so we will definitely test it out, Thanks for sharing!

Steve

[maherhome]

Woke up last night thinking maybe you were talking about switching at 33.3 MHz.  Could you confirm that you were switching at 66.6 MHz, resulting in a 33.3 MHz clock?   Thanks!

Steve

[[dk]]

Yes it was a clock (not switching) running at a 30 ns period (~33.3 MHz).