Beckhoff ELX3312, Operating Manual

Page: 60 / 88

Parameterization and programming
ELX3312 and ELX3314 60 Version: 1.3.0
The terminal constantly records measured values and saves the raw values from its A/D converter in the
ADC raw value objects 0x80nE:01, 0x80nE:02. After each recording of the analog signal, the correction
calculation takes place with the vendor and user calibration data as well as the user scaling, if these are
activated (see following picture).
Fig. 43: Calculation of process data
Calculation
Calculation Designation
X
ADC
Output of the A/D converter
X
F
Output value after the filter
Y
H
= (X
ADC
– B
H
) x A
H
x 2
-14
Measured value after vendor calibration,
Y
A
= (Y
H
– B
A
) x A
A
x 2
-14
Measured value after vendor and user calibration
Y
S
= Y
A
x A
S
x 2
-16
+ B
S
Measured value following user scaling
Key
Name Designation Index
X
ADC
Output value of the A/D converter 0x80nE:01
X
F
Output value after the filter -
B
H
Vendor calibration offset (not changeable) 0x80nF:01
A
H
Vendor calibration gain (not changeable) 0x80nF:02
B
A
User calibration offset (can be activated via index 0x80n0:0A) 0x80n0:17
A
A
User calibration gain (can be activated via index 0x80n0:0A) 0x80n0:18
B
S
User scaling offset (can be activated via index 0x80n0:01) 0x80n0:11
A
S
User scaling gain (can be activated via index 0x80n0:01) 0x80n0:12
Y
S
Process data for controller -
Measurement result
The accuracy of the result may be reduced if the measured value is smaller than 32767 / 4 due to
one or more multiplications.
Also see about this
2
Configuration data (vendor-specific) [
}
75]
5.3.7 Producer Codeword
Producer Codeword
The vendor reserves the authority for the basic calibration of the terminals. The Producer codeword
is therefore at present reserved.