Hamilton Electronics EPHUM011 - Manual (Page 24)

pH ARC Sensors Modbus RTU Programmer ’ s Manual (EPHUM011)
624300/01 page 24 / 67
2.5.5 Secondary Measurement Channels 1-16
pH ARC Sensors do allow access to secondary measurement values (16 in total). The access to the
individual SMC depends on the operator level. The available SMC are defined in register 2048
according to the selected operator level and the sensor type (see chapter 2.5.1).
2.5.5.1 Description of SMC
The registers defined here give a plain text ASCII description of each available SMC.
Start
register Number of
registers Reg1 … Reg8
16 ASCII characters
Modbus
function code Read
access Write
access
Address 8 Description of each SMC 3, 4 U/A/S none
Figure 2.5.5.1.1: Definition of registers at Address
Description Address Plain Text
(16 ASCII) Description
SMC1 2464 R glass Resistance of the pH glass
SMC2 2496 R reference Resistance of the reference electrode
SMC3 2528 R auxiliary Resistance of the auxiliary electrode
SMC4 2560 E pH vs. ref Electrical potential between glass and reference electrode
SMC5 2592 E SG vs. ref Electrical potential between solution ground and reference
electrode
SMC6 2624 E aux vs. ref Electrical potential between auxiliary electrode and reference
electrode
SMC7 2656 E reference Electrical potential between reference electrode and electrical
ground
SMC8 2688 pH act Current pH value (3-seconds-reading)
SMC9 2720 T act Current T value (3-seconds-reading)
Figure 2.5.5.1.2: Full list of starting register addresses for the plain text ASCII description of each SMC
Example:
Command: SMC 1 text Modbus address: 2464 Length: 8 Type: 3 Read
Parameter: Text
Format: Character
Value:
R glass
Figure 2.5.5.1.3: Example to read the description of SMC1 at address 2464. It is “ R glass ” .