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7.
Reference zero absolute/relative
FMod-IPAXESCTRL is able to work with the exact
position coming from each FMod-IPxxMOT. In that case
we speak about zero absolute, because the “0” displayed
on FMod-IPAXESCTRL means that the corresponding axis
POSITION
register is really at position 0.
Sometimes it is useful to set a new reference “0” that is
not the “0” set during the calibration (homing) of the
FMod-IPxxMOT.
There are two cases to perform that action:
1)
A new “0” is send to the corresponding FMod-
IPxxMOT
POSITION
register; absolute zero is changed,
and the software minimum and maximum limitation
(
INPUTMIN
&
INPUTMAX
registers) could make no
sense because their reference “0” is changed.
Especially if a home position (homing) is done at
power-up.
2)
FMod-IPxxMOT
POSITION
register is kept unchanged
but an offset value will be added locally in FMod-
IPAXESCTRL.
In both cases the value displayed is the same, and all the
interaction. But with the “0 relative reference” the inside
FMod-IPxxMOT reference will not change. That is very
important when a range of suitable position (e.g. hardware
limitation) is ative.
What is made inside (when key function is pressed):
“Set position zero absolute” :
AXIS1POSITIONOFFSET
= 0
“Set position zero relative” :
AXIS1POSITION
=
POSITION
FMod-IPDCMOT (Axis1)
FMod-IPAXESCTRL
Local position,
display, save goal
position
+
-
POSITION
AXIS1POSITIONOFFSET
Trackball, key
interaction, set goal
position
INPUT
+
FMod-IPAXESCTRL User Manual v.1.1