08-27-2009 12:29 PM
08-28-2009 06:28 PM - edited 08-28-2009 06:29 PM
Regards,
Dan King
11-24-2010 06:20 PM
I got the same problem when I used NI-5661 to look at the Power Spectrum of my signal (I got about 60dB loss).
However, when I do "Self-test" for the device, it has passed. And I used NI-5671 to generate a sine wave with -20dBm reference level and NI-5661 to look at the signal, I got the signal at about -25 dBm (just few dB loss). All the LEDs are working fine as I transmit and receive the signal.
When I tried to change the Reference level of NI-5661 using Property Node, the attenuation changed accordingly and the noise floor changed, but not the amplitude of the signal.
Could you please give me some advice?
Thank you very much.
Phuong
11-29-2010 04:56 PM
Hello Phuong,
A 20dBm different is pretty big, how are you cabling your 5661? Have you tried using different RF cables? When was the last time your device was calibrated?
11-30-2010 05:09 PM
Thanks for your quick response, Christian. I cabled 5661 with the included cables as instructed: PXI 10 MHz I/O to 10 MHz OUT, 10 MHz OUT to CLK IN, OUTPUT to CH 0.
I used different RF cable to connect OUTPUT of RFSG 5610 to INPUT of RFSA 5600. When I used Test Panels and RFSG 5610 to generate a signal and RFSA 5600 to receive the signal, I got NO dB loss if Power level at the RFSG <= -10 dBm, and I got 25 dB loss if Power level at the RFSG >= -5 dBm.
The calibration time of my devices:
PXI 5600: 8/4/2008 (Exp: 8/4/2009)
PXI 5142: 8/7/2008 (Exp: 8/7/2010)
PXI 5610: 12/12/2008 (Exp: 12/12/2009)
PXI 5441: 12/11/2008 (Exp: 12/11/2010)
PXI 4461: 01/13/2009 (Exp: 01/13/2010)
I am not sure if the expired calibration has impacted my test results or the hardware has been damaged. Please give me some advice.
With my real test hooked up, I got up to 60 dB loss.
Thank you very much for your help.
Phuong
12-01-2010 10:04 AM
Hello Phuong,
In light of your recent post I recommend that you send the board in for repair, there is probably a damaged component on the board.
You will need to create a service request using the technical support link here
Once you call in an RMA can be set up for your device.
Regards
12-01-2010 10:58 AM
12-01-2010 11:09 AM
Hello Phuong,
I would recommend sending in the entire unit, that way the repair technician can test the entire system. I do not know what the cost of repairs will be but the RMA co-ordinator you contact will be able to tell you the repair costs.
Regards
12-01-2010 06:03 PM
12-02-2010 10:28 AM
Hello Phuong,
This is a strange situation, which may require you to repair LabVIEW, however you will need to post in the LabVIEW discussion forums, an Engineer more familiar with our software product line will assist you.
Regards