I do not hear any specific relay noise in my modules; however, the test lab has a noticeable background noise level (air handlers, HVAC). Can you scan the modules one at a time to determine if all of the relays are "loud"? Perhaps only one module needs to be exchanged. Only someone from NI could state whether the audible "thrip" is normal.
As for the "alternate scanning method", it would not work for several reasons. First, the 1010 combo chassis is setup for the last PXI slot to be the controller for the SCXI modules with the default to multi-plex all of the data through channel 0. You cannot address the SCXI modules on other 6052E channels (although you could use an 1180 feedthrough panel to access the other 6052E channels). In addition, you would not gain any scan
performance increase. For all three modules on channel 0 of the 6052E, the fastest (theoretical) scan rate would be (333kHz/48 channels) or 6.9 kHz. Scanning 16 channels on each of three channels (0,1,2) would not give any performance gains - and in fact, would actually be slower due to interchannel delays and the individual addressing and muxing of three separate modules at different times. In addition, parallel reads on the DAQ card would only cause buffer errors as the AI Config VI assigns the 6052E buffer to a unique Task ID. Parallel AI Reads on a single Task ID would cause buffer hardware errors due to simultaneous attempts to access hardware that is already in use.
