synchrinization delay between NI 9239 and NI 9225

[wsaall]

I have synchrinization problem when I am acquiring data from a NI-9239  (currents) and NI-9225 (Voltages) for three phases in LabVIEW FPGA 8.6.  Synchronization between the channels is important to my applications and when I feed the same signal into both modules, I see a phase difference between them.  I know that this is due to the delta-sigma ADC used on the NI-9239 and NI-9225, but am not sure how to compensate for it.

note: chassis (cRIO-9102)

Eng. Waheeb S. Alwan
Instrumentation/Control Engineer
Pioneers Technical Systems

[AdnanZ · Accepted solution]

I had the same problem sometime back. Have a look at the following article; it has an example as well:

How to Compensate for Different Group Delays with C Series Modules in LabVIEW FPGA

[mishkin]

Hi wsaall,

The 9239 module is a voltage input module, not current (maybe you're calculating the current value yourself). The link Adnan Z posted provides a good explanation of the problem. Please let me know if this does not work out for you.