User Manual
E727T0005, valid for E-727
BRO, 2019-06-28
Physik Instrumente (PI) GmbH & Co. KG, Auf der Roemerstrasse 1, 76228 Karlsruhe, Germany
Page 88 / 240
Phone +49 721 4846-0, Fax +49 721 4846-1019, Email
Scaled Value:
The range depends on the axis and can be set by the coefficients of the polynomial used for
Mechanics linearization (see "Digital processing" for details):
ScaledValue = GAIN * NormalizedValue
where
OFFSET corresponds to the
Sensor Mech. Correction 1
parameter, ID 0x02000200
GAIN corresponds to the
Sensor Mech. Correction 2
parameter, ID 0x02000300
If no linearization is necessary, the other coefficients of the Mechanics linearization polynomial can
be set to zero (parameter IDs 0x02000400, 0x02000500, 0x02000600).
Note that in PIMikroMove, these parameters are available in the
Sensor Mechanics 4
to
Sensor
Mechanics 7
parameter groups in the
Device Parameter Configuration
window.
How to calculate the values to set for OFFSET and GAIN:
GAIN = (MaxScaledValue - MinScaledValue) / (MaxNormalizedValue - MinNormalizedValue)
OFFSET = MaxScaledValue - GAIN * MaxNormalizedValue
The values of "MinScaledValue" and "MaxScaledValue" depend on the travel range of the axis with
which the analog input line is to be used:
"MinScaledValue" is given by the TMN? answer (is defined by the
Range Limit min
parameter, ID =
0x07000000), and "MaxScaledValue" is given by the TMX? answer (is defined by the
Range Limit
max
parameter, ID = 0x07000001).
The values of "MinNormalizedValue" and "MaxNormalizedValue" depend on the range of the
external signal applied to the analog input line. See the examples below.
For all examples, the following is assumed:
Input signal channel 4 (pins 2 and 9 of
Analog I/O
) is to be used with axis 1.
Via the
Sensor Range Factor
parameter, a maximum input range of -10 to +10 V is
selected for input signal channel 4.
Axis 1 has the following travel range:
MinScaledValue = -20 µm
MaxScaledValue = +120 µm
Example 1:
The full range of -10 V to +10 V is to be used (this is recommended for highest resolution).
MinNormalizedValue = -100
MaxNormalizedValue = +100
GAIN = (120 - (-20)) / (100 - (-100)) = 0.7
OFFSET = 120 - 0.7 * 100 = 50
ScaledValue = 50 + 0.7 * NormalizedValue