Lika IF51, User Manual

Page: 51 / 56

IF51
11 - Free programmable linearisation
This programmable feature allows the user to convert a linear motion to a non-
linear analogue output and vice versa. There are 16 programmable interpolation
points available, which can be set in any desired distance over the full
conversion range. Between two points, the unit uses linear interpolation.
Therefore it is advisable to use more points in a section with strong curves and
only a few points where the curvature is lower.
To specify your desired linearisation curve, you must set the
Linearisation
Mode
register to either 1 or 2 first.
Use registers
P1(x)
to
P16(x)
to specify the coordinates on the x-axis. These are
the analogue output values that the unit normally would generate according to
the actual encoder position. These settings must be expressed in percentage (%)
of the full scale.
Now enter the desired values to registers
P1(y)
to
P16(y)
. These are the values
that the analogue output will generate instead of the x- values.
As an example, the value set next to
P2(y)
will be used instead of the encoder
value P2(x) etc.
NOTE
•
X-registers must use continuously increasing settings, i.e.
P1(x)
item
must have the lowest setting and
P16(x)
item must have the highest
setting.
•
All entries use a percentage format which is xx.xxx% of the full scale.
Setting 0.000% means zero output while setting 100.000% means full
scale output.
•
With
Linearisation Mode
set to
1
, it is compulsory to set
P1(x)
register
to 0% and
P16(x)
register to 100% . Linearization is defined in the
positive range only and the negative range will be a mirror image of the
positive range with reference to zero.
•
With
Linearisation Mode
set to
2
, it is compulsory to set
P1(x)
register
to –100% and
P16(x)
register to +100% . This enables the user to set
curves which are not symmetric to the zero position.
x
y
P1(x)= 0%
P1(y)=10%
Linearisation Mode = 1
x
y
Linearisation Mode = 2
P1(x)= -100%
P1(y)= 95%
P8(x)= 0%
P8(y)= 80%
P16(x)=+100%
P16(y)= -60%
*)
P16(x)=100%
P16(y)= 80%
* ) Output mode = 0
You can display your curve on the PC screen or by means of an external
oscilloscope. For this, select TOOLS in the menu bar of the OS3.2 PC operator
software, then press TEST command and finally ANALOGUE VOLTAGE FUNCTION
MAN IF51 I_E 1.1.odt 11 - Free programmable linearisation 51 / 56