DAQ if scan rate with external timebase, what will happpen to channel rate

[may lee]

PCI-MIO-16XE-50: I make scan clock use a much more stable external timebase by Alternate Clcok rate spec in AI clock config.vi. In this case, what happens to channel clock? Which timebase will it use? The external one or the internal one? If the internal one, does it mean that the final data from DAQ is not stable and accurate? Shall I configure both scan rate and channel rate using the external timebase?

[ryanm]

When an external timebase changed by using the RTSI bus as described in http://digital.ni.com/public.nsf/3efedde4322fef19862567740067f3cc/5601c8268d625a3c86256cf50071199d?OpenDocument, this will change the DAQ cards Master Timebase. The MasterTimebase signal, or Onboard Clock, is the timebase from which all other internally generated clocks and timebases on the board are derived. Therefore, both the scan and channel rate be based on the external timebase.