create double pulse with defined . t_on1 t_off1, t_on2, t_off2

[andreastanner]

Good morning everybody!

Can anybody help me with the above mentioned problem? I am using the

pci 6601 timer counter card and would like to create a double pulse with

defined times t_on1 t_off1, t_on2, t_off2, which all are in the us dimension.

Thanks a lot,

Andreas

[Kevin_Price]

There isn't a direct way to do that with a 6601.  For some reason, NI has never supported buffered pulse train output with counters.  I've been waiting for such a capability since the LabVIEW 4 era.

The next best way I can think of would use 2 separate counters of the 6601 and then run both of their individual outputs through an external OR logic chip.  The correct timing relationships could be programmed if the 2nd counter is triggered by the output of the 1st counter.

-Kevin P.

[andreastanner]

Thanks a lot; this is one possibility. How about using two counters; one acts as a clock; the other

as a counter of rising edges of the clock. The value of the second counter could be compared to fixed values.

That way, one could design a pulse pattern with a set of a few AND / OR gates...or?

[Kevin_Price]

The value of the second counter could be compared to...

The concept is ok, but in real life your comparisons and decisions must happen up in the software level.  Unless you were running a real-time OS, you couldn't get regular deterministic timing of your software execution.  And even in RT, it'd be difficult if not impossible to achieve the micro-second timing you're after.

Note: a double-pulse would be pretty simple to setup using correlated DIO on an M-series board if you've got any budget for data acq hardware...

-Kevin P.