IX34510a_e.doc / Apr-11
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5.4.
Basic Modes of Operation
5.4.1.
Normal SSI display
Normal operation provides calculation of the display value from the SSI encoder data and the
settings of the scaling factors. Negative values can be achieved by corresponding setting of the
zero-position, or by inversion of the direction bit.
To set the unit up without problem, it is best to use the following sequence of steps:
Set all basic registers according to the encoder type you use, as shown in section 4.1.
For better comprehension, use first all initial settings as shown in the list
(xxx = according to need)
M-Factor
:
1.000
Direction
:
0
D-Factor
:
1.000
Error
:
xxx
P-Factor
:
0
Error P
:
xxx
Decimal Point
:
000000
Round-Loop
:
0
Display
:
0
Time
:
xxx
Hi bit
:
Reset
:
no
Lo bit
:
see 5.2 and 5.3 *)
0-Position
:
0
*) Please evaluate 19 bits only to avoid overflow
These settings ensure that the unit displays the pure SSI encoder information at first.
Move your encoder now from a “lower” position towards a “higher” position according
to your own definition of "low" and "high". When also the display changes from lower to
higher values, your own definition of directions matches with the encoder definition. If
not, change the setting of “Direction” from “0” to “1” now to receive the desired sense
of direction (changes after further parameter settings may cause different results) **)
Set the desired zero position, either by entering the numeric value to the “0-Position”
register, or by using the Reset function as described previously. Your zero definition will
divide the range into a positive and a negative zone.
At this time you are free to set all other registers according to your needs.
The subsequent drawings show the principle of evaluation with use of a 13 bit single turn
encoder, with the direction bit set to either “0” or to “1”, and with the zero position register
set to “1024” **)
**) Subject of correct sequence with parameter settings
DA6-SSI/A-U
