Aalborg Vortex - Manual (Page 72)

67
6.1.3 Analog 4-20 mA channel#2 output calibration
1. Connect a certified high sensitivity multi meter set for the current
measurement to pins 3 (+) and 4 (-) of the TB3 terminal connector.
2. Write 4000 counts to the DAC2 channel: !11,WRITE,1,4000[CR]
3. Read current with the meter and designate it to Reading_4000_mA variable.
4. Write 400 counts to the DAC1 channel: !11,WRITE,1,400CR]
5. Read current with the meter and designate it to Reading_400_mA variable.
6. Calculate Out2_Scale_mA value:
Out2_Scale_mA = 3600 / (Reading_4000_mA - Reading_400_mA)
7. Calculate Out2_Offset_mA value:
Out2_Offset_mA = - (Reading_4000_mA/10 - Reading_400_mA) X Out2_Scale_mA
8. Save Out2_Scale_mA in to the EEPROM: !11,MW,34,Y[CR]
Save Out2_Offset_mA in to the EEPROM: !11,MW,35,Z[CR]
Where: Y – the calculated Out2_Scale_mA value.
Z – the calculated Out2_Offset_mA value.