6. Commissioning, operation
Zero adjustment
Output data
0x21
XX
0x23
HI
The respective correction value can be calculated as follows:
Correction value = -
Correction value: Digit value which is programmed into the instrument via service 0x23.
Offset: Deviation of the zero point from the set point in bar
Span: MBE - MBA in bar
Changes only take effect after a reset.
Zero adjustment, example 1:
A pressure transmitter with a measuring range of -1 ... +2.5 bar has a zero offset of +10 mbar, then one
would correct:
Measuring range -1 ... +2.5 bar
Display value 10 mbar too high
Correction value = -
0.010 bar
Correction value = -
WIKA operating instructions pressure transmitter model D-1x-7
Input data
XX
0x21
LO
0x23
Offset
x 50,000
Span
Span: 3.5 bar
Offset: +0.010 bar
Offset
x 50,000
Span
x 50,000
3.5 bar
HI
LO
HI
LO
Correction value = -143
Explanation
Read zero adjustment
Write zero adjustment
0xFF71
Output data
0x23
0xFF
GB
0x71
21