I have a very serious problem with PCI-6509. (NI Japan has no real technical support division, so I have been always going on resolution by myself for a long time)
I have built an automatic measurement system with LabVIEW in which PCI-6509 is to send trigger signals to current generation devices through MOS FET relays. All channels can get the device triggered indivisually, but when several channels are simultanously used a couple of channels become unable to get it triggered.
I have confirmed the "number threshold" and find out half of each port(8 channels) is the capacity. This must be caused by less trigger current and the circuit design problem(--;
On the other hand, MOS FET specification is followings:
LED trigger current: avg 1.0mA, max 3.0mA PCI-6509 current : 24mA
Looking into the specifications above, I cannot understand why such a problem occured. Can anybody give me practical advice for the resolution?