Hamilton Electronics EPHUM011 Configuration of the Analog Interfaces, Available Analog Interfaces

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

2.4Configuration of the Analog Interfaces

2.4.1 Available Analog Interfaces

A pH ARC Sensor has two individual physical analog interfaces that have identical functionalities, but can be configured independently from each other.

Analog Output Interface 1 (AO1)

Analog Output Interface 2 (AO2)

The number of analog interfaces is defined in register 4320.

Start	Number of	Reg1 / Reg2	Modbus	Read	Write
register	registers		function code	access	access
4320	2	Available analog interfaces	3, 4	U/A/S	none

Figure 2.4.1.1: Definition of register 4320.

Command: Avail analog interfaces		Modbus address: 4320	Length: 2	Type: 3	Read
Parameter:	Available analog
	interfaces
Format:	Hex
Value:	0x03

Figure 2.4.1.2: Example to read the available analog interfaces. The answer is “0x03”meaning that there exists an Analog Interface 1 (AO1) and an Analog Interface 2 (AO2).

2.4.2 Available Analog Interface Modes

With register 4322, the available analog interface modes for AO1 and AO2 are defined

Start		Number of	Reg1 /		Reg3 /	Reg5 /	Reg7 /	Modbus	Read	Write
register		registers	Reg2		Reg4	Reg6	Reg8	function	access	access
								code
4322	8		Available		Available	reserved	reserved	3,4	U/A/S	none
			Analog		Analog
			Interface		Interface
			Modes for		Modes
			AO1		for AO2
Figure 2.4.2.1: Definition of register 4322. It defines the analog interface modes available for AO1 and
AO2. The analog interface modes are described in Figure 2.4.2.2.
Code		Analog Interface		Description
(Hex)		Mode
0x00		4-20 mA inactive		Analog interface deactivated
0x01		4-20 mA fixed		Set to a constant output value for current loop testing
0x02		4-20 mA linear		Linear output of measurement (PMC1 / 6)
0x04		4-20 mA bilinear		Bilinear output of measurement (PMC1 / 6)

Figure 2.4.2.2: Definition of the analog interface modes, valid for both AO1 and AO2.

Command: Analog Interface Modes		Modbus address: 4322		Length: 8	Type: 3	Read
Parameter:	Available Analog	Available Analog	reserved		reserved
	Interface Modes for	Interface Modes for
	AO1	AO2
Format:	Hex	Hex	Hex		Hex
Value:	0x07	0x07	0x0		0x0

Figure 2.4.2.3: Example to read register 4322: all modes defined in figure 2.4.2.2 are available for both AO1 and AO2.

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