08-26-2008 11:57 PM
Is it possible to synchronise NI-RFGS and NI-RFSA devices using the NI-TCLK library?
I have a PXI system with a PXIe-5672 waveform generator / upconverter and a PXI-5661 downconverter / digitizer. I would like to synchronise them so they start transmitting / recording at the same time. I believe in general the NI-TCLK library can be used to achieve this?
I can't wok out how to use it. The "niTCLK configure for homogenous trigger" vi takes an array of "sessions", however I don't have "RFSA Get Session Reference" or "RFSG Get Session Reference" functions.
Is it possible to use the NI-TCLK library with RFSA and RFSG? If so, how do you configure it?
Thanks in advance
David
Labview 8.0 / Windows XP
08-27-2008 05:53 PM
Hi David,
You will have to handle the session from the SCOPE and the FGEN independently for that you will need to use a VI called: “niRFSG Get Fgen Session.vi” and “niRFSA Get Scope Session.vi”. They are not at the functions palette but you can find them at: “C:\Program Files\National Instruments\LabVIEW 8.5\instr.lib\niRFSG\niRFSG.llb”.
I have some code that I need to test that is using TClk with RFSA and RFSG, if you don’t mind waiting for me a little bit I would test the code and post it on Friday.
08-27-2008 07:32 PM
Thanks for the advice, I will look into using the Fgen and Scope sessions.
David
08-27-2008 11:56 PM
I have attemtpted to synchronise transmitter and receiver using the TCLK library and the RFSG get Fgen session / RFSA get Scope session vi's. Both RFSA and RFSG have been initialised and have no start trigger set, and neither have been started. Their session references have been wired to a niTCLK configure for homogenous triggers vi.
However when I run TCLK synchronise or TCLK initiate I get the following erors.
Is it possible to use niTCLK with the digitiser in DDC mode? When I do not synchronise the RFSA (so only the RFSG is connected to the TCLK configure and initiate) I do not get the errors, but obviousy the RFSG is only synchronising with itself
niTClk Initiate.vi:1<append>
<B>Session index (starts at zero): </B>1
<B>Error reported by the instrument driver: </B>
TClk synchronization is not currently supported with the DDC enabled.
Device: PXI1Slot5
Property: Min Sample Rate
Invalid Value: 1.0e6
Maximum Value: 100.0e6
Status Code: -214237
08-29-2008 11:33 AM
Hi David,
The error message might be due to the version of RFSA that you have. I would suggest upgrading the driver version. I tested the example with: ni-fgen 2.6, ni-scope 3.5, ni-rfsg 1.4 and ni-rfsa 2.1.
The example attached is a very simple set up, and as you will see on the block diagram the 5671 and the 5661 are set as upconverter and downconverters mode respectively. Then you use their partners’ drivers to complete the job.
Let me know if you have any questions.