Using Analog Input from M-Series DAQ card for Feedback in motion controller PCI-7350 Card

[yanxinix]

Hi, I have an analogue input from SC-2345 into M-series DAQ card. Now, I wish to configure this analogue input as analogue feedback in the motion controller PCI-7350 card. I am not able to use the analogue input in PCI-7350 as it requires an additional SCB-68 and it will create some noise problems. Is it possible to to use analogue input from the DAQ instead?

[Jochen]

Hi yanxinix,

the analog feedback is part of the real-time loop running on the PCI-7350. If you acquire the analog signal with an M-Series device this would mean, that you have to transfer the acquired signal to the PCI-7350 via the PCI bus. This requires software interaction on the PC and a significant delay and jitter caused by the low-priority host communication process on the PCI-7350.

Besides the fact that the PCI-7350 doesn't accept feedback signals from the PCI-bus anyway, the process described would add a feedback delay of about 5 to 10 ms and a high amount of jitter, making stable control behavior impossible.

So I'm afraid, this approach is not feasible. If you want to use analog feedback with a PCI-7350 you have to use the analog inputs on this board.

Kind regards,

Jochen Klier

National Instruments