LabVIEW RT Trad DAQ Stops Working on Software Update

[alukindo]

Happy New Year 2008!

After a PXI RT-controller was repaired and had software updated, the system exhibited floating behavior for all strain gage channels via an SCXI-1520 and SCXI-1314 connector block. The system lives in a PXI/SCXI combo chassis i.e. PXI-1011 and was put together in 2003 using Trad DAQ. The system worked fine since 2003 until recently. I have tried to revert the controller back to old software used in 2003 i.e: LabVIEW RT 7.0 and Trad DAQ 3.0.1 but the controller will not even let me install the 7.0.0 RT software after I reformatted it. The controller will however, happilly accept higher software versions. I have two host PCs one with legacy software (LV and LV RT 7.0) and one with newer software (LV and LV RT 8.2/8.5).

Extensive troubleshooting was done to isolate faulty hardware component but to no avail. This behavior was later duplicated on a second system and this channel float behavior continues to exhibit itself even when using a regular battery (full bridge, no excitation)

****By floating I mean that the measured channel drifts by small voltage amounts until it becomes outside of the configured range.

The system works OK in DAQMx and will also work OK in Traditional DAQ ---when using a controller with Windows OS. The problem only happens when operating under remote connection under LV RT OS.

Any pointers to the possible cause of this behavior?

Thanks

Anthony