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Hamilton Electronics EPHUM011 User Manual

Page 25

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pH ARC Sensors Modbus RTU Programmer

s Manual (EPHUM011)

624300/01

page 25 / 67

2.5.5.2

Reading the measurement value of SMC

The registers defined here are used to read the measurement values of each SMC.

Start reg.

Num-
ber of
reg.

Reg1 / Reg2

Reg3 / Reg4

Reg5 / Reg6

Modbus
function
code

Read
access

Write
access

Address

6

Physical unit

Measurement
value of SMC

Standard
deviation

3, 4

U/A/S

none

Figure 2.5.5.2.1: Definition of register at Address. Measurement value of each SMC.

Description

Address

Text

Unit

Min value

Max value

SMC1

2472

R glass

MOhm

30

600

SMC2

2504

R reference

kOhm

0.25

100

SMC3

2536

R auxiliary

kOhm

0.25

100

SMC4

2568

E pH vs. ref

mV

-900

900

SMC5

2600

E SG vs. ref

mV

-900

900

SMC6

2632

E aux vs. ref

mV

-50

50

SMC7

2664

E reference

mV

-900

900

SMC8

2696

pH act

pH

-0.5

14

SMC9

2728

T act

K

253

403

Figure 2.5.5.2.2: Full list of register addresses for the measurement values of SMC1 to SMC9

Example:

Command: SMC1 read

Modbus address:

2472

Length:

6

Type:

3

Read

Parameter:

Unit

Value

Standard dev.

Format:

Hex

Float

Float

Value:

0x8000

247.56

0.02

Figure 2.5.5.2.3: Example to read register 2472. Physical unit is MOhm (0x8000), the measurement

value of SMC1 is 247.66 MOhm, standard deviation of SMC1 is 0.02 MOhm