08-05-2015 08:49 AM
Hello All,
I am trying to program the FPGA of a VST 5644R for a simple RF-loopback. The objective
is to send a signal to the FPGA, transmit it through RF-OUT and receive the same in RF-IN.
Subsequently, the received signal is sent back to the host...
To this end, I would like to know the steps needed to configure the RF-subsystems of the 5644R
VST, before I send the signal to the FPGA of the device... I looked at the VSA/VSG example and
came up with a guess which I have shown in the attachment..
Can anyone have a look at the attachment and let me know if it is correct or something else
needs to be done?? Also why does a coercion dot appear the "Open Register Bus" VI??
Any advice or inputs no matter how little would be helpful..
With best regards,
S. Kumar Raja
08-06-2015 01:30 PM
Hi Kumar,
You only need to call the basecard VIs once overall, not once for RF in and once for RF out. The basecard library contains settings common to both RF in and out. The register bus instance 0 and 1 can access the basecard, RF in, and RF out registers so you only need one instance of the bus (although two instances work just as well).
In the Simple VSA/G project register bus instance 0 is the only way to access the acquistion engine, and register bus instance 1 is the only way to access the generation engine. This is the code that's missing from your VI. You asked about configuring the subsystems, however, and for that what you have looks like it should work.
08-07-2015 02:42 AM
Thanks Shawn for your reply...
I also would like to know if the sequence of VIs also ensures the locking of LO between RF-IN and
RF-OUT.. My objective is to export the LO of RF-OUT and use it as an external LO for RF-IN...
I have external cable connecting LO-OUT of RF-OUT to LO-IN of RF-IN in the VST..
With best regards,
S. Kumar Raja
08-07-2015 04:12 PM - edited 08-07-2015 04:13 PM
Since you're exporting the LO from RF out, I would setup RF out first. You can run the full RF out setup chain and then run the RF in setup chain (instead of parallelizing the setup). That way there is an external LO available to RF in when it is configured. Otherwise, RF in may throw an error about the missing LO.
08-12-2015 03:34 AM
Thanks Shawn for the reply... I will try what you said and let you know the outcome...