pH ARC SensorsModbus RTU Programmer’s Manual (EPHUM011)
624300/01 page 42/ 67
2.7.3.2.2 Product calibration:Assignment
After successfulinitial measurement a correct value must be assigned to the initially stored
measurementdata.
This is achievedby writing the correct calibration value to register 5322.
Start
register Number of
registers Reg1/ Reg2 Modbus
function code Read
access Write
access
5322 2 pHv alue [pH] 16 none A/S
Figure 2.7.3.2.2.1:Definition of register 5322
Command: CP6:Assignment Modbusaddress: 5322 Length: 2Type: 16 Write
Parameter: Value
Format: Float
Value: 7.2
Figure 2.7.3.2.2.2:Example to assign a calibration value to the above performed initial measurement.
This is achieved by writing the correct pH value.
From nowon the sensor is measuring using the here performed product calibration.
The calibration status(register 5318) is 0x14000000 meaning that a correct value has been assigned
and that the product calibration is active (see figure 2.7.4.1.1).
2.7.3.2.3 Product calibration:Cancel
To cancel an activeproduct calibration or an active initial measurement the command 0x02 is written to
register 5340.
Command: CP6:Cancel Modbusaddress: 5340 Length: 2Type: 16 Write
Parameter: Command
Format: Hex
Value: 0x02
Figure 2.7.3.2.3.1:Example t o cancel an active product calibration or an initial measurement.W riting
the command 0x02(cancel) to register 5340.
Performing thisacti ont he productcalibration or any initial measurements are canceled. The values of
the prior productcalibration are removed from the sensor’smemory. From now on the sensor is
measuring usingits prior CP1 / CP2 standard calibration.
The sensor’scalibration status (register 5318) will be reading0x00 again (see figure 2.7.4.1.1).