Is it possible to extract a regular, high-frequency clock from the NI 4462?
I need to synchronise with another card (a PulseBlaster) which requires a 100 MHz clock: either card can be the main source, but they must stay perfectly in sync.
(Both cards have onboard 100 MHz crystal oscillator modules; the PulseBlaster's one is socketed, so would be easy to connect an external source intead)
I'm using the PCI version, so the 10 MHz PXI star clock isn't available. The 10 MHz or 20 MHz clocks that DAQmx usually exports don't seem to be available for routing on this device.
I can't use the Sampleclock, because that is variable (~ 25.6 MHz, changing with sample-freq) and because it is only active when the 4462 is actually making measurements.
Also, this clock needs to be either 100 MHz, or a simple integer fraction of it (eg 10 MHz, so that a PLL can re-generate the 100 MHz).
At the moment, the best option looks to be to solder onto the 4462's crystal oscillator output pin - but that's a really ugly way to do it....has anyone had any experience of making the relevant modifications?
Is there a better place to connect to? I'd prefer to use the RTSI bus connector, but despite the tantalising hints in the documentation, it doesn't seem possible to get the 10/20 MHz master timebase out: there is
a pin called RTSI7/RTSI_OSC, but this is permanently low.