TClk to synchronise PXI 5401 and PXI 5122

[kmh]

How can I synchronize a PXI 5401 and PXI 5122?

I want the PXI 5122 to start aquisition exactly when PXI 5401 starts generation.I want both this devices to trigger at the same time.

Can TClk be used for this?

[JonBowers]

Hi Kiran,

The TClk line is used when one external trigger is needed for all devices. Using a TClk trigger however you will not get the aquisition to start imediately because it will wait for the next rising edge of the TClk signal before triggering the devices. FOr more information about this refer to LabVIEW>>Help>>NI TClk Syncronisation Help. This method does however require an external digital trigger. If you just want both devices to start at the same time but not have to trigger them externally you can just trigger the 5122 from the 5401. To do this route the Out Start Trigger of the 5401 to a RTSI line (Real Time System Intergration Bus) using the niFGEN Route Signal Out vi, then trigger the 5122 from this RTSI line.

Hope this helps

Jon B
Applications Engineer
NIUK and Ireland

[Drew Creel]

NI-TClk is a method of synchronizing clocks and triggers so that each device that receives a TClk-synchronized trigger starts generation/acquisition at the same time and remains in sync for the duration of the generation/acquisition.  This synchronization scheme accounts for trigger propagation, analog path, and other delays that affect how long it takes a device to start after receiving a trigger.

Unfortunately, NI-TClk synchronization is not supported for the PXI-5401 Function Generator.  The next best thing would be to configure the 5401 and 5122 to use an External Reference Clock source (like the PXI_Clk10 signal in your PXI Chassis) and then configure the 5122 for either edge triggering or digital triggering.  For digital triggering, route the Out Start Trigger from the 5401 to a RTSI line and use this RTSI line as the digital trigger source like Jon described.

Drew Creel
Software Engineer
NI Signal Generators

[Carlukos]

Hi Jon

I have seen you have reply the question how synchronize a PXI 5401 and PXI 5122.

I have a similar problem because I want to synchronize a PXI 5401 and PXI 5124, could you help me to solve this problem?

[hannahW]

Hi Carlukos,

The 5124 and 5122 have similar features, so you could use the same solution described by Drew to synchronise the two devices

"The next best thing would be to configure the 5401 and 5122 to use an External Reference Clock source (like the PXI_Clk10 signal in your PXI Chassis) and then configure the 5122 for either edge triggering or digital triggering.  For digital triggering, route the Out Start Trigger from the 5401 to a RTSI line and use this RTSI line as the digital trigger source like Jon described."

This will allow you to trigger the devices so they begin the acquisition/generation at the same time

Hannah

[Rob Hingle]

Our previous programmer used the RTSI 0 line and a 6602 timing module in an attempt to sync the arb to the scope.  It does not quite work.  First he configures both the 5122 and the 5421 to trigger on RTSI 0 (though it's a string for the scope and an integer for the arb).  Then he merges the errors from the config vi's and runs his "start pulse" vi which sends out a pulse (to our amplifier under test) and presumably triggers both the scope and the arb.  This vi sets up two pulses on the 6602: one (TIMER/ctr1) exports to the arb and the scope (Counter Output Event to /DIGI/PXI_Trig0 and /ARB/PXI_Trig0) while the other (TIMER/ctr0) is triggered off the first one and I believe this is the one that outputs to the amplifier. In the end, the pulse to the amplifier is perfectly in sync with the waveform, but the scope seems to trigger about a milisecond early, varying with each pulse how early (+/- 500us)  It is frustrating that this is so difficult to do in Labview when it is one of the most basic functions of benchtop equipment.  If anyone can help me with this, I will send the vi's, but because of issues with the previous programmer, I'm basically on my own here and don't understand much of what's in them.
Thanks whoever can help

[Ogy]

Hi
How can I synchronize NI PCI 5401 and NI PCI 5102 via TClk. I want to use external 1kHz square clock source. Is it possible to use this?
Thanks

Igor