How do i alter the timebase when using Measure Period (DAQ-STC).vi

[Ross@UL]

Dear All

I am using the Measure Period VI in Labview 6 to get the period of an external signal. The VI works fine but the internal timebase used by default in the VI (20MHz) is too high a frequency (i am looking at periods of between 1 and 4 seconds).

I am using an E series board and from the help files i understand there is another internal timebase (100KHz) which alolows measurement of periods of up to 167 secs rather than 838ms with the 20Mhz timebase.

How do i select this timebase for the VI, there is even a note on the VI which says 'This calculation assumes max timebase is selected as the source'.

Please Help, i'm almost finished my VI apart from this!!

Regards Ros
s

[RobertoBozzolo]

Looking in the vi diagram you will find Counter Source (stc).vi (immediately to the right of Counter Group Config.vi), that uses as an input a cluster located off to the left on the front panel of Measure period.vi. This cluster contains an option to set the internal timebase used: choose the desired 100 kHz.
Next delete the Counter Get Attribute.vi with the internal Max Timebase constant wired to the Attribute ID input and wire a (double)constant of 100000 to the Y terminal of the division at the far right of the diagram.
That's all.
Roberto