Hamilton Electronics EPHUM011 Reading and Writing the Baud Rate, Reading the Baud Rate Limits

pH ARC Sensors Modbus RTU Programmer’s Manual (EPHUM011)

2.3.2Baud Rate

2.3.2.1Reading and Writing the Baud Rate

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

Start	Number of	Reg1 / Reg2	Modbus	Read	Write
register	registers		function code	access	access
4102	2	Baud rate code	3, 4, 16	U/A/S	S
		(definition see below)
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.

2.3.2.2Reading the Baud Rate Limits

The baud rate limits can be read in register 4104.

Start	Number of		Reg1 / Reg2			Reg3 / Reg4	Modbus	Read	Write
register	registers						function code	access	access
4104	4		Min. Baud rate			Max. Baud rate	3, 4	U/A/S	none
			code			code
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).

624300/01 page 8 / 67