Error 200077

[Shaswata1998]

Hi All,

I am trying to run a pressurized membrane filtration apparatus in my lab using LabView. I am using NI USB 6001 device to aquire analog input from pressure transducer (voltage based signal). Previously, someone wrote a LabView VI which can acquire data in RSE mode. However, when I try to acquire input in differential mode (using the same previously written VI) after making necessary connections in NI USB 6001, I get an error 200077. The VI runs fine for data aquisition in RSE mode. However, it gives the error when I try to make data aquisition in differential mode by changing the input terminal configuration of 'DAQmx create channel' to 'differential' from 'RSE'. Can you please help me to figure out the problem so that I can aquire transducer data in differential mode. I have attached the VI and the error message.

Thanks

[ZYOng]

You can only use 4 DIFF or 8 RSE channels.

Reference:USB-6001 Specifications

[Shaswata1998]

Thanks a lot for your help.

I want to filter the noisy data from the transducer before logging it in as it is acquired. Is it okay to include a median filter just after the DAQmx read? Is there a way to filter the data just after DAQmx start task inside the loop?

[ZYOng]

USB-6001 does not have any built-in filter feature. You can only do post-processing on the data returned from DAQmx Read VI.

Have you tested reading data using RSE mode? Are you sure that you need DIFF mode? Depending on the type of pressure transducer, RSE might be a better choice. See Table 1 in Field Wiring and Noise Considerations for Analog Signals