Dear people of RTL-mailing list,
We at NBG-Industrial (Location Nederweert, Netherlands) are trying to sample/count a
TTL-signal with a frequency of 200 kHz
(or as high as posssible). We use a PIO-24 card (ISA-based) to generate an interrupt at
each pulse. The interrupthandler in RTlinux is used to increase a counter. In a
seperate
thread, which starts up every second, the time is measured and the frequency is
calculated.
The precision of the frequency was measured while linux itself was heavily loaded
(compiling
a kernel). 20 kHz is the highest frequency which can be measured without a deviation.
25 kHz
is still measured reasonably well(a deviation of -6 Hz once in the 200 times). But
frequencies
above 30 kHz are measured with a deviation of minimal 10 Hz almost every measurement
(which
is too large). Is there a way too improve this performance? For instance optimizing
core.c/core.o?
Yours sincerely,
Erwin Triepels
The code is added as an attachmant
Fsm.doc
