Continuous Gen Start Trigger

[Taitoshi]

Hello All,

I am very new to DAQmx and am attempting something I am sure is very simple.  I did perform a search of the docs and the forums but did not find what I need (this could very well be because I don't know what I am looking for :)).

I am generating digital signalling using the DAQmxCfgBurstHandshakingTimingImportClock and have no issues generating samples out relative to an incoming clock.  The issue I have is that I need to align the start of the outgoing samples to another incoming signal lets call it Sync (runs at a lower rate then the clock).  When I see the positive edge transition on the Sync signal I want the generation to go into continuous generation mode.  After this initial check I don't require any check of the Sync signal as the entire system is syncronous and once aligned it will stay aligned.

I am using a 6534 Digital IO device and attempted to use DAQmxCfgDigEdgeStartTrig  but it indicated that it would not work with BurstHandshaking mode.  I appreciate any assistance you can give.  Let me know if you need further clarification.

Here is the setup:

DAQmxErrChk (DAQmxCreateTask("",&taskHandleSrc));

DAQmxErrChk (DAQmxCreateDOChan(taskHandleSrc,"/Dev1/port0","",DAQmx_Val_ChanForAllLines));

DAQmxErrChk (DAQmxCfgSampClkTiming(taskHandleSrc,"/Dev1/port5/PFI4",2000000.0,DAQmx_Val_Rising,DAQmx_Val_ContSamps,1024));

DAQmxErrChk (DAQmxCfgBurstHandshakingTimingImportClock(taskHandleSrc,DAQmx_Val_ContSamps,1024,2000000.0,"/Dev1/PFI4",DAQmx_Val_Rising,DAQmx_Val_High, DAQmx_Val_ActiveHigh));

DAQmxErrChk (DAQmxWriteDigitalU8(taskHandleSrc,fsrc_read_size,0,10.0,DAQmx_Val_GroupByChannel,data_src,NULL,NULL));

DAQmxErrChk (DAQmxStartTask(taskHandleSrc));

[e-Cash-Money]

Hello Taitoshi,

Triggering is not supported when the timing is configured to use Handshaking.

If you do not need to use Handshaking and use Pattern I/O instead (you can use an internal or external clock with Pattern I/O), then it is possible to trigger your acquisition.

I hope this helps!

Message Edited by E.Lee on 07-25-2005 02:26 PM

[Taitoshi]

E.Lee,

Thanks for your reply unfortunately (as is always the case) a higher priority item has come up so I will not be able to try this for a couple of days.  I have not used pattern IO so I will look it up. 

T