Hamilton Electronics EPHUM011 manual Secondary Measurement Channels, Description of SMC

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

2.5.5 Secondary Measurement Channels 1-16

pH ARC Sensors do allow access to secondary measurement values (16 in total). The access to the individual SMC depends on the operator level. The available SMC are defined in register 2048 according to the selected operator level and the sensor type (see chapter 2.5.1).

2.5.5.1Description of SMC

The registers defined here give a plain text ASCII description of each available SMC.

Start	Number of		Reg1 … Reg8		Modbus	Read	Write
register	registers		16 ASCII characters		function code	access	access
Address	8		Description of each SMC		3, 4	U/A/S	none
Figure 2.5.5.1.1: Definition of registers at Address
Description		Address	Plain Text	Description
			(16 ASCII)
SMC1		2464	R glass	Resistance of the pH glass
SMC2		2496	R reference	Resistance of the reference electrode
SMC3		2528	R auxiliary	Resistance of the auxiliary electrode
SMC4		2560	E pH vs. ref	Electrical potential between glass and reference electrode
SMC5		2592	E SG vs. ref	Electrical potential between solution ground and reference
				electrode
SMC6		2624	E aux vs. ref	Electrical potential between auxiliary electrode and reference
				electrode
SMC7		2656	E reference	Electrical potential between reference electrode and electrical
				ground
SMC8		2688	pH act	Current pH value (3-seconds-reading)
SMC9		2720	T act	Current T value (3-seconds-reading)

Figure 2.5.5.1.2: Full list of starting register addresses for the plain text ASCII description of each SMC Example:

Command: SMC 1 text		Modbus address: 2464	Length: 8	Type: 3	Read
Parameter:	Text
Format:	Character
Value:	R glass

Figure 2.5.5.1.3: Example to read the description of SMC1 at address 2464. It is “R glass”.

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