CompuScope SDK Manua.. - Egmont Instruments

actually passes through zero and the CompuScope is never triggered. To resolve this problem,
simply raise the trigger level to one that corresponds to 1 Volt or so. Using the wrong external
trigger input range can also cause this problem.
Q: The program runs, but why is the data capture incorrect?
A: The order in which CompuScope parameter setup routines are called for data capture is important.
gage_trigger_control should be called after gage_input_control, which should be called after
gage_capture_mode. It is recommended that the programmer use the SetBoard() routine to
implement CompuScope settings, since this routine calls all setup routines in the correct order.
The SetBoard () routine resides in app_supp.c , which is included with every C sample program.
Q: Why is Multiple Record mode behaving erratically in my program?
A: The order in which the driver routines are called is important. gage_multiple_record should be
called before gage_capture_mode, gage_input_control or gage_trigger_control. Also, if you
change the Multiple Record settings, gage_trigger_control must be called again. . It is
recommended that the programmer use the SetBoard() routine to implement CompuScope
settings, since this routine calls all setup routines in the correct order. The SetBoard () routine
resides in app_supp.c , which is included with every C sample program.
Q: Why I am not able to properly capture the data with an external clock?
A: There can be several reasons for this. The nature of the required external clock signal is different
for each CompuScope model. The voltage levels, signal shape, duty cycle and allowed frequency
range must also be respected. Please see your hardware manual for these details. Many
CompuScopes terminate the external clock input with a 50 Ohm load for good signal propagation.
The users signal must then be capable of driving a 50 Ohm load. Finally, the external clock
function is optional on some models, so make sure that your CompuScope is actually equipped
with the external clock option.
Most CompuScopes have a minimum operating frequency. Consequently, the clock signal cannot
be turned off while the CompuScope is operating. It is best to have a free-running clock source
that is always active.
Another important point is to correctly set the external clock frequency in your application
program. The drivers have no other means of knowing this frequency. The drivers need to know
the external clock frequency in order to internally set low level timing delays on the CompuScope.
If you tell the drivers the incorrect external clock frequency, this may lead to incorrect
CompuScope operation.
CompuScope API Reference Manual
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