Refresh Of The Encoder Counting - Zapi EPS-AC0 SWs&ENC User Manual

Together with this possibility DEBUG OUTPUT provides many other special
functions (that are described in paragraph 11.4.6.4). For example it is possible to
use the hand set to read the voltage from the second twin pot wiper (CPOC2 on
CNA#8) on the reading SET POINT POT of the hand set. It is just enough to turn
DEBUG OUTPUT to level 13.
U
Don't forget to turn DEBUG OUTPUT to Level 15 after finished the test.

12.7 Refresh of the encoder counting

After the initial alignment, the position of the steered wheel is measured with the
encoder. The encoder counting is initialized at the first edge (falling or rising does
not matter) of the straight ahead sensor with a null value (or with the SET ENC AT
180 value depending by the configuration of the toggle switches). Then, further
refresh of the encoder counting is triggered with the following handling:
1) Application with limited steered wheel angle. No further refresh after the first
falling edge on the straight ahead toggle switch.
2) Application with unlimited steered wheel angle. The encoder counting is
refreshed at least once for every full steered wheel revolution. The refreshing is
triggered when the WHEEL ANGLE is inside the range 90 +/- 30 degrees or
inside the range -90 +/-30 degrees. Then, at the first falling edge of the straight
ahead sensor, the encoder counting is refreshed with a null value (if the WHEEL
ANGLE is inside the range 0+/-30 degrees) or with a SET ENC AT 180 ( if the
WHEEL ANGLE is inside the range 180 +/-30 degrees). After every refresh,
further refresh is inhibited until a new trigger condition. As a consequence, if the
driver turns the steered wheel always in the same direction, the encoder
counting will be refreshed on a falling edge on the straight ahead toggle switch
occurring with WHEEL ANGLE close to 0 degrees. If the driver reverses the
turning direction, the encoder counting will be refreshed on a falling edge on the
straight ahead toggle switch occurring with WHEEL ANGLE close to 180
degrees.
At last, if the refresh is triggered but the falling edge occurs meanwhile the
WHEEL ANGLE is neither into the 0+/-30 degrees nor into the 180 +/-30
degrees, the refresh will not be executed.
Working that way, there is not drift accumulation in the encoder counting because a
refresh is always performed at least every steered wheel revolution.
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