National Instruments E Series User Manual

Page 106

Appendix D Common Questions

DAQCard E Series User Manual

D-4



National Instruments Corporation

What is the difference in timebases between the Am9513 counter/timer and the
DAQ-STC?

The DAQ-STC-based boards have a 20 MHz timebase. The

Am9513-based boards have a 1 or 5 MHz timebase.

The counter/timer examples supplied with NI-DAQ are not compatible with an
DAQCard E Series card. Where can I find examples to illustrate the use of the
DAQ-STC as a general-purpose counter/timer?

If you are using the NI-DAQ language interface and a C compiler under

DOS, a new subdirectory called

GPCTR

, which lies beneath the

examples

directory, contains 16 examples of the most common uses

of the DAQ-STC.

Will the counter/timer applications that I wrote previously work with the
DAQ-STC?

If you are using the NI-DAQ with LabVIEW, some of your applications

drawn using the CTR VIs will still run. However, there are many
differences in the counters between the DAQCard E Series and other
boards; the counter numbers are different, timebase selections are
different, the DAQ-STC counters are 24-bit counters (unlike the 16-bit
counters on boards without the DAQ-STC).

If you are using the NI-DAQ language interface, such as

LabWindows/CVI, the answer is, no, the counter/time applications that
you wrote previously will not work with the DAQ-STC. You must use
the GPCTR functions; ICTR and CTR functions will not work with the
DAQ-STC. The GPCTR functions have the same capabilities as the
ICTR and CTR functions, plus more, but you must rewrite the
application with the GPCTR function calls.

I’m using one of the general-purpose counter/timers on my DAQCard E Series
card, but I do not see the counter/timer output on the I/O connector. What am
I doing wrong?

If you are using NI-DAQ language interface or LabWindows/CVI, you

must configure the output line to output the signal to the I/O connector.
Use the

Select_Signal

call in NI-DAQ to configure the output line.

By default, all timing I/O lines except EXTSTROBE* are tri-stated.