how can i synchronize a 4472 DSA using another instrument as a master

[weatherhound]

I want to eliminate jitter on my captured signals. therefore I want to synchronize my 4472 off of my function generator (which has a synch out). Can I use the external trig input on my 4472 PCI card and the digital trigger from the function generator? thanks in advance

[Bryan F]

Hello --

In general, DSA devices do not support external clocking. There are two reasons for this, both of which relate to the nature of the delta-sigma analog-to-digital converters (ADCs) employed on the 4472. First, these converters are actually clocked by a signal much faster than the sample rate of interest (generally in the MHz range). This fast clock is generated internally on the 4472. Secondly, this clock must be quite steady to yield useful results. Delta-sigmas will not perform well given unsteady clocks, and intermittent clocking is common in applications requiring external sample clocks.

Because of these constraints, the PCI-4472 cannot accept an external clock.

If you use a PXI-6653 timing and synchronizaiton module, it does become pos
sible to route an external clock to a PXI (not PCI) 4472. However, the clock must run at 128 or 256 times the desired 4472 sampling rate.

Hope that helps!