Getting events from DAQ board counter in LAbView

[sergey 671]

I use a AT-MIO64E-3 DAQ board that will be replaced by PCI6071E in the near future. These days I work on a datalogger project (Win NT 4, LabView 6i) that should sample data from various data sources (DAQ boards, a reflective memory board etc.) and show / save them.

It's important to synchronize all sampling actions to the DAQ board's ones (with lower frequency: it's ~ 10KHz for the DAQ board and ~ 0.2 - 1KHz for other data sources.

I've set-up the the internal counter 0 of the sampling board to produce some signal to use it as clock inside LabView. To get it into Labveiw I used the "Generate occurence on DAQ event" VI with event type 4. I saw that the counter worked as needed (I've connected a scope and saw the
signal generated), but I could not manage the occurence to work - nothing happened.

1. Are there any examples for using "Generate occurence on DAQ event" in mode 4 (with counters) ? I understood that the counter types are board-dependent:
what type of counters have AT-MIO64E-3 and PCI6071E ?

2. I've read in the LabView's help that it's bad practice to get more than 500 occurences per second. If I have to work with frequencies ~ 1KHz, is there another way to handle such events ?

Thank you,
Sergey.

[Filipe A.]

Sergey;

I think you don't need to use occurences to synchronize those devices. If you set up a counter operation on the board and use the counter output pulse train as a clock to the other devices, you would have all devices synchronized by hardware, without having the need to envolve the NI-DAQ driver on it.
Firt you need to synchronize the NI DAQ board analog input with the counter, and then generates a pulse train on that counter, which will be used as clock for the other devices.
To synchronize Analog Input with counters, you can refer to the attached Application Note. To generate a pulse train on your counter, you can refer to the Labview shipping example named "Generate Pulse Train (DAQ-STC).vi" which can be found at Search Examples->I/O Interfaces->Data Ac
quisition->Counters->Continuous Pulse Train.
Hope this helps.
Filipe

[sergey 671]

The problem is that I do not need to syncronize hardware devices. What I have to do is to read from these devices (reflective memory - RM) into my LabView application upon the DAQ sampling board's clock. The data in the RM appears "automagically" from my point of view - I can suppose that it's always up-to date when I read it.