Hamilton Electronics EPHUM011 - Manual (Page 7)

pH ARC Sensors Modbus RTU Programmer ’ s Manual (EPHUM011)
624300/01 page 7 / 67
2.3 Configuration of the serial RS485 Interface
Factory settings of the RS485:
Parity is none, 1 start bit, 8 data bits, 2 stop bits (in total: 11 bits).
2.3.1 Device Address
2.3.1.1 Reading and Writing the Device Address
The sensor specific device address can be read and written in register 4096.
Start
register
Number of
registers Reg1 / Reg2 Modbus
function code Read
access Write
access
4096 2 device address 3, 4, 16 U/A/S S
Figure 2.3.1.1.1: Definition of register 4096.
Command: Com address Modbus address: 4096 Length: 2 Type: 3 Read
Parameter: Modbus address
Format: Decimal
Value:
1
Figure 2.3.1.1.2: Example to read the device address.
The device address can be set by S (Specialist), default value is 1.
Command: Com address Modbus address: 4096 Length: 2 Type: 16
Write
Parameter: Modbus address
Format: Decimal
Value: 3
Figure 2.3.1.1.3: Example to set the device address to 3.
2.3.1.2 Reading the Device Address Limits
The device address limits can be read in register 4098.
Start
register Number of
registers Reg1 / Reg2 Reg3 / Reg4 Modbus
function code Read
access Write
access
4098 4 Min. device
address Max. device
address 3, 4 U/A/S none
Figure 2.3.1.2.1: Definition of register 4098.
Command: Com address limits Modbus address: 4098 Length: 4 Type: 3 Read
Parameter: Min value Max value
Format: Decimal Decimal
Value: 1 32
Figure 2.3.1.2.2: Example to read the device address limits: Min = 1, Max = 32.