Hamilton Electronics EPHUM011 manual Description of PA9 Moving Average

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

2.6.2.1Description of PA9 (Moving Average)

In register 3360, a plain text ASCII description of PA9 is given.

Start	Number of	Reg1 … Reg8	Modbus	Read	Write
register	registers	16 ASCII characters	function code	access	access
3360	8	Description of PA9	3, 4	U/A/S	none

Figure 2.6.2.1.1: Definition of register 3360.

Command: Moving average text		Modbus address: 3360	Length: 8	Type: 3	Read
Parameter:	Text
Format:	Character
Value:	Moving average

Figure 2.6.2.1.2: Example to read the description for “Moving average“.

2.6.2.2Selecting the Physical Unit and Writing the Value for PA9

In register 3368, the available physical units for PA9 are defined.

Start	Number of		Reg1 / Reg2		Modbus		Read	Write
register	registers		(bitwise defined)		function code		access	access
3368	2		Available physical units for PA9		3, 4		U/A/S	none
Figure 2.6.2.2.1: Definition of register 3368.
Command: Moving average av. units				Modbus address: 3368	Length: 2	Type: 3		Read
Parameter:		Units
Format:		Hex
Value:		0x01

Figure 2.6.2.2.2: Example to read the available physical units for PA9. The only one available here is “none”(0x01). For the definition of the physical units see chapter 2.5.1.

Start	Number of	Reg1 / Reg2	Reg3 / Reg4	Modbus	Read	Write
register	registers	(bitwise defined)		function code	access	access
3370	4	Select physical unit	Value for PA9	16	none	S
		for PA9	(1-16, default: 2)

Figure 2.6.2.2.3: Definition of register 3370. Only one bit for the physical unit can be set. PA9 can be set to the value 1-16. A value of 1 does not influence the response time of the sensor, a value of 16 increases the response time of the sensor to 48 s.

By writing to register 3370 the active physical unit for PA9 can be selected by choosing one of the physical units that are defined in register 3368. The value of the parameter can be set as well.

Command: Moving average		Modbus address: 3370	Length: 4	Type: 16	Write
Parameter:	Unit	Value
Format:	Hex	Decimal
Value:	0x01	12

Figure 2.6.2.2.4: Example to set the physical unit of PA9 to “none”(0x01) and the value of the moving average to 12.

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