Manufacturer Specific Profile Area
CAN-CBX_Pt100
Manual • Doc.-No.: C.3032.21 / Rev. 1.1
Page 107 of 120
8.11.10 Calibration Data
The analog inputs of the CAN-CBX_Pt100 module have been calibrated by the manufacturer before
delivery. The following calibrations have been made:
• the higher measuring current (ca. 400
O
A)
• the lower measuring current (ca. 40
O
A)
• ADC gain PGA=2
• ADC gain PGA=3
• ADC gain PGA=4
The parameters determined during calibration are contained in the following objects and can be
changed. Normally, an adjustment of the objects by the user is not necessary.
An adjustment by the user is only advisable in the object “offset”(2510
h
), to compensate the line
resistances.
With command Restore Default Parameters (1011
h
) the initial setting of the calibration data
adjusted by esd are reactivated.
8.11.10.1 Calibration and Process/Field-Value Calculation
In the following formulas the parameter names are shown without the channel identifier at the end
of the parameter names to improve the clarity.
The calculations shown in the following are automatically done by the local firmware. For the user
the corrected measuring values are accessible by the process variables PV.
Field-Value Calculation
AI FV
adc raw value
ADC PGA
_
_
_
_
=
2
with
adc_raw value
:
A/D-converter value after addition and averaging
AI_FV
[Object 9100
h
]:
Field Value
ADC_PGA
[Object 2400
h
]:
ADC-gain