PCI 4472 and PCI 6230 Synchronization questions

[Zhengxin]

Thanks for your reply.

I also noticed that it can be synchronized by using SampleClock. I attached a demo program that uses this approach.

I found that the accuracy is depending on the rate of Sample Clock. What I did is I use a function generator to generate a 24Hz sinusoidal wave as the analog data and also use the sync pulses(which is 24Hz square wave ) from the function generator as the digital tach input. So the correct angular velocity should be 1440rpm. The fluctuation amplitude of the angular velocity and phase lag is inversely proportional to the Sample Clock. If I put 10k as the Sample Clock and 5k as samples per channel,the maximum fluctuation in the angular velocity is about 0.3, and 0.03 for Sample Clock at 100k.This is the reason I want to use the Sample Clock Timebase that is much faster than the Sample Clock and I believe it will give relatively accurate results.

Hope you can find me another solution to this. Thank you.

Zhengxin

[Doug_L._Bear]

Off the top of my head I can't think of a solution around this issue other than hacking the RTSI lines.  I will research this further and post later on Friday.

[Doug_L._Bear]

I have talked with a couple other people over here, including some in R&D and it appears you're only two options are to hack your RTSI cable and manually route the signal or to use the Sample Clock instead of the Sample Clock Timebase.  I have looked at the device routing of many other devices to see if those would afford you different options but not of them seem to have access to RTSI 8 unfortunately.