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cc:
Subject:Shaft encoder routines installed
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Hello everyone,

The shaft encoder software is now working (I think).  Shaft encoder
routines "sencdrNN.icb" are available for NN= 12 to 19.


Please note the following if you are going to use shaft encoders:

* The routines sample the sensor at a rate of 250 Hertz, not the 1000
Hertz specified in the notes.  Therefore, sensor transitions can only
be detected at this rate or more slowly.

* Probably it is most suitable to put the shaft encoder sensor on the
final drive shaft or the next to final geardown.

* The velocities are calculated approx. 8 times per second, not the 16
times per second specified in the notes.

* Each shaft encoder routine that is installed will consume
approximately 4% of the overall CPU time.


The reason for the changes in the spec's of the routines is due to the
excessive CPU load required to sample the sensors at the 1000 Hz. rate
previously specified.  The routines implemented in this fashion
consume about 12% CPU time PER ENCODER.

If for some reason you require this faster sampling rate, routines
"fencdrNN.icb" are available.  These routines also sample the
velocities at twice the rate of the "sencdrNN" routines, so you will
get velocity readings one-half as large when using these routines.
BUT---there should be no reason to use the routines---move your shaft
encoder down to a slower shaft and use the other routines.  Give your
CPU a break.


Please send bugs to fredm@amt.

	- Fred