Synchronizing multiple NI-5411s

Question

Hello all,
I have a recent project that involves simultaneous generation of waveforms across multiple NI-5411s (PCI version). These 5411s will generate a set of waveforms continuously until the user stops the program.
My initial idea was to have one of the 5411 as a "master" device, which will output a start trigger pulse to the other three "slave" 5411s. The implementation will be similar to this example program here.
As I was looking around for alternative implementation / additional information, I found one possible alternative, where the "master" 5411 will send a SYNC pulse (not a start trigger) to the "slave" 5411s via RTSI, by using the "niFgen Export Signal" VI. Of interest is the option to output a "Synchronization Pulse" that promises "absolute synchronization between two or more signal generators (5404/5411/5431 only)." The "slave" 5411s will call the "niFgen Configure Synchronization" VI to read in the synchronization pulse. However, I am not able to find any related example programs in LabVIEW or on the NI website.
My questions are:
1) What is the difference between using a start trigger and using the "synchronization pulse"?
2) Are there any examples that demonstrate the use of this "synchronization pulse" to synchronize the generation of multiple 5411s? 
3) Is there a benchmark that shows how tight the synchronization is for this "synchronization pulse", say versus a normal start trigger?
Thanks in advance!
Best regards,
Victor

Answer 1

Hi Victor
I think you are on the right track: 
I have just one more question about the configuration - does this mean that instead of exporting the normal start trigger from the master, we export the synchronization pulse instead, and tell the slaves to use this as the substitute start trigger?
1) Configure 20MHz local clock from master to be shared with slaves for PLL.
2) Configure synchronization pulse to be shared from master to slaves on RTSI0 (for example)
3) Configure start trigger for all slaves on their RTSI0.
4) Start generation.
If you look at the section that begins with "To phase lock NI PXI-5411/5431 signal generators, complete the following steps" on the instructions that James provided here: http://zone.ni.com/reference/en-XX/help/370524R-01/siggenhelp/master_slave_operation/, it is pretty much as you are describing above except with PXI devices. 
We should be able to do the same with PCI devices as follows:
Set the master device to send any valid Reference clock to the PLL reference input connector.
Set up the slave devices with the I/O connector as the PLL reference source.
Set the PLL reference frequency parameter to the clock frequency sent by the master. The devices are now frequency locked to the master.
To further phase lock the devices, set up the master to send the trigger signal on one of the RTSI trigger lines.
Set up the slaves to receive their trigger signal on the RTSI trigger line.
Set up the master to send the device_SYNC signal on the RTSI trigger line and the slaves to receive the device_SYNC signal on the same RTSI trigger line.
Start the waveform generation on all the slaves.
Start the waveform generation on the master.
Keep in mind that the 5411 was End-of-Lifed around 2008 and is based on our older software architecture known as TDAQ, so there is not that much example code floating around anymore (if there were even any to begin with).
Jason L.