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Hamilton Electronics EPHUM011 User Manual

Page 8

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pH ARC Sensors Modbus RTU Programmer

s Manual (EPHUM011)

624300/01

page 8 / 67

2.3.2 Baud Rate

2.3.2.1

Reading and Writing the Baud Rate

The baud rate can be read and written in register 4102.

Start
register

Number of
registers

Reg1 / Reg2

Modbus
function code

Read
access

Write
access

4102

2

Baud rate code
(definition see below)

3, 4, 16

U/A/S

S

Figure 2.3.2.1.1: Definition of register 4102.

The code for the baud rate is defined as follows:

Baud rate

4800

9600

19200

38400

57600

115200

Code

2

3

4

5

6

7

Figure 2.3.2.1.2: Code for the baud rates.

Command: Com baud rate

Modbus address:

4102

Length:

2

Type:

3

Read

Parameter:

Baud rate code

Format:

Decimal

Value:

4

Figure 2.3.2.1.3: Example to read the baud rate code, 4 corresponds 19200 baud.

The baud rate can be set by S (Specialist), default is 19200.

Command: Com baud rate

Modbus address:

4102

Length:

2

Type:

16

Write

Parameter:

Baud rate code

Format:

Decimal

Value:

5

Figure 2.3.2.1.4: Example to set the baud rate to 38400 baud with code 5.

2.3.2.2

Reading the Baud Rate Limits

The baud rate limits can be read in register 4104.

Start
register

Number of
registers

Reg1 / Reg2

Reg3 / Reg4

Modbus
function code

Read
access

Write
access

4104

4

Min. Baud rate
code

Max. Baud rate
code

3, 4

U/A/S

none

Figure 2.3.2.2.1: Definition of register 4104.

Command: Com baud limits

Modbus address:

4104

Length:

4

Type:

3

Read

Parameter:

Min Baud rate code

Max Baud rate code

Format:

Decimal

Decimal

Value:

2

7

Figure 2.3.2.2.2: Example to read the baud rate code limits: Min = 2, Max = 7 (see Figure 2.3.2.1.2).