Connecting a trigger pulse from PXI-6683H/PFI1 to PXIe-5172 digitizer

[PikesPeakNIUser]

I have a PXI chassis with some digital IO boards, a PXI-6683H IRIG-B board, and a PXIe-5172 8 channel digitizer. I'm using LabWindows/CVI 2017, and trying to connect a trigger from the IRIG board to the digitizer.

I need to use PFI1 or PFI2 on the 6683H as a trigger input. The input pulse is a 60 ns TTL pulse every 50 ms. When the trigger occurs, I need to initiate a 60 us read on up to six channels of the 5172, at the full speed of 250 MSPS.

I can already read the data on the digitizer, I just don't know how to connect the trigger from the IRIG-B board to the digitizer. I've looked at a lot of NISync routines, but didn't see any examples.

Thanks in advance for your help. Any ideas would be appreciated.

[AgentAstronaut]

Hi PikesPeakNIUser,

Use the niSync Connect Trigger Terminals (VI) to route the PFI line to the trig bus. Then have the scope look at the trig bus.

http://zone.ni.com/reference/en-XX/help/373629B-01/nisynclv/nisync_connect_trigger_terminals/

Make sure you are distributing the triggers correctly in MAX if the scope and 6683 are on different switches.

http://digital.ni.com/public.nsf/allkb/CA9A49FA50393C4186256DC200774E2B

Post back if you need further clarification.

[PikesPeakNIUser]

Thanks for the reply. 

I looked over the VI routine, and here's what I came up with. The choices for the destination in niSync_ConnectTrigTerminals below (NISYNC_VAL_PXISTAR) also include PXI_STAR[0-16], PXI_TRIG[0-7], PXIe-DStarB[0-16], and PXIe-DStarC.

The only choices when configuring the input trigger to the PXIe-5172 digitizer are as follows.

Using niScope_ConfigureTriggerEdge, the choices are Channel[0-7] or External_TRIG.

Using niScope_configureTriggerDigital, the choices are RTSI[0-6], PFI[0-2], or PXI_Star_Trigger.

// Map a trigger from the PXI-6683H to the digitizer
vStatus = niSync_ConnectTrigTerminals (pCommMgr->m_pIRIGBModule->m_VISession, NISYNC_VAL_PFI1, NISYNC_VAL_PXISTAR, 
                        NISYNC_VAL_SYNC_CLK_ASYNC, NISYNC_VAL_DONT_INVERT, NISYNC_VAL_UPDATE_EDGE_RISING);

if (vStatus != VI_SUCCESS) {
	ViChar description[512];
	niSync_error_message( pMod->m_VISession, vStatus, description );
	printf("      **** InitializeModule(%d): Error Mapping PFI1 to PXI_STAR0 trigger %s (%s)\n", tmod, pMod->m_moduleName, description );
} else {
	printf("      %s port PFI1 mapped to PXI_STAR_TRIGGER0.\n", pMod->m_moduleName );
}

The only commonality is the PXI Star Trigger, but the wording is not exact, and I get the following error when trying to map the trigger from PFI1 to PXI_Star_Trigger:

**** InitializeModule(0): Error Mapping PFI1 to PXI_STAR0 trigger NI PXI-6683H (The specified destination terminal is invalid for this operation.)

 The two boards are on the same switch in the backplane. I used NIMax to check that out.

I don't know if I'm using the correct routines, so if you have any other ideas, I'd appreciate it!

Thanks!

[AgentAstronaut · Accepted solution]

RTSI0 should be PXI_Trig0, RSTI1 is Trig1, and so on.

[PikesPeakNIUser]

Thanks. That worked. RTSI0 can receive a trigger from PXI_TRIG0.

Thanks!