Hamilton Electronics EPHUM011 manual Defining a Constant Current Output for Testing

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

Attention:

When assigning measurement values to 4-20 mA analog output by using register 4378 / 4506, you need to consider the following:

The PMC you have mapped to AO1 / AO2 (register 4364 / 4492)

The physical unit currently in use for the selected PMC (register 2090 for PMC1 (pH) and

register 2410 for PMC6 (temperature).

Therefore, when the operator redefines one of the register 4364 / 4492, 2090 / 2410, the definitions of the register 4378 / 4506 should be reviewed. If not, the current output at the 4-20 mA interfaces may be wrong.

Note:

The physical unit of the analog output corresponds always to the unit that is set for the selected PMC (register 2090 for PMC1 or register 2410 for PMC6). Accordingly, not only the pH value is selectable at the 4-20 mA interface, but also mV values, degrees centigrade or Kelvin.

Example:

Register 4364 is set to 1 (PMC1 is mapped to AO1).

Register 2090 is set to 0x1000 (the unit “pH”is assigned to PMC1). Register 4378 is set to 2 and 10 (4 mA = pH 2, 20 mA = pH 10).

The sensor reads currently pH 4, the output at the 4-20 mA is accordingly 8 mA.

The operator now re-assigns register 2090 to the value of 0x200000 (unit = mV), but does not modify all other registers. The sensor is still at pH 4 and reads now +170 mV. At the analog output, as 20 mA is programmed to a value of 10 by register 4378, the current will go to the maximum value of 20 mA.

This will generate an interface warning “4-20 mA current set point not met”.

2.4.5.7Defining a Constant Current Output for Testing

Note:

For constant current output, the AO1 / AO2 must be set to analog interface mode 0x01:

Start	Number of	Reg1 / Reg2	Modbus	Read	Write
register	registers		function code	access	access
4384	2	Constant current output value for	3, 4, 16	U/A/S	S
		AO1 [mA]
4512	2	Constant current output value for	3, 4, 16	U/A/S	S
		AO2 [mA]

Figure 2.4.5.7.1: Definition of register 4384 / 4512.

Command: Fixed value AO1			Modbus address: 4384		Length: 2	Type: 3	Read
Parameter:	Fixed value [mA]
Format:	Float
Value:	10

Figure 2.4.5.7.2: Example to read the constant current output in mode 0x01 for AO1. It is set to 10 mA.

624300/01

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Contents PH ARC Sensors Important Notice Sensor Identification and Information Configuration of the Serial RS485 InterfaceConfiguration of the Analog Interfaces Configuration of the MeasurementIntroduction Visiferm do Modbus RTU Programmer’s Manualp/n 624179/01EPHUM011 0x03 Operator levels and PasswordsReading / Setting Operator Level General0x0B 18111978 Changing Passwords for Operator Level0x30 0x0C 18111978Reading the Device Address Limits Configuration of the serial RS485 InterfaceDevice Address Reading and Writing the Device AddressBaud Rate Reading and Writing the Baud RateReading the Baud Rate Limits 0x07 Configuration of the Analog InterfacesAvailable Analog Interfaces Available Analog Interface ModesMA interface #2 Selection of an Analog Interface ModeDescription of the Analog Interfaces 1 MA interface #1Configuration of the 4-20 mA Interface 0x210x01 PH ARC Sensors Modbus RTU Programmer’s Manual EPHUM011 Reading the Selected Physical Unit for Analog Interface 0x001000Defining the Measurement Values for 4, 12 and 20 mA Output PH ARC sensor 4-20mA inte rface linear Defining a Constant Current Output for Testing 0x010001 99186 99742 Reading the Internally Measured Output CurrentDefinition of Measurement Channels and Physical Units MeasurementSpecial 0x201000 Primary Measurement Channel 1 pHDescription of PMC1 Selecting the Physical Unit for PMC1Reading the measurement value of PMC1 0x1000 02503 0x000x200000 175.9922 0x00 954.6541 0x06 Primary Measurement Channel 6 TemperatureDescription of PMC6 Selecting the Physical Unit for PMC60x04 24.35834 0x00 130 Input of an Externally Measured TemperatureDefinition of the Measurement Status for PMC1 / PMC6 Reading the measurement value of PMC6Description of SMC Secondary Measurement Channels0x8000 247.56 Reading the measurement value of SMCAvailable Parameters Configuration of the MeasurementEffect of Moving Average n=1 vs n=16 2 PA9 Moving AverageSelecting the Physical Unit and Writing the Value for PA9 Description of PA9 Moving AverageReading all Values for PA9 3 PA12 Moving Average R Description of PA12 Moving Average RSelecting the Physical Unit and Writing the Value for PA12 Reading all Values for PA12 Available Calibration Points CalibrationCP2 Definitions of Calibration PointsCalibration Points 1 and 2 Standard Calibration CP1CP6 Calibration Point 6 Product CalibrationCalibration at CP1 and CP2 Standard Calibration Calibration ProcedurePH ARC Sensors Modbus RTU Programmer’s Manual EPHUM011 Choose one of the calibration points CP1 or CP2 0x00000000 0x00001000 Calibration at CP6 Product Calibration 100200 Product calibration Initial measurement Definition of the commands for product calibrationProduct calibration Assignment Product calibration CancelProduct calibration Restore product calibration Product calibration Restore standard calibrationReading the Calibration Status of CP1 and CP2 Reading the Calibration Status0x00000080 0x00001000 0x00000180 0x00001000Reading the Calibration Status of CP6 Product Calibration 0x14000000 0x00001000 0x01000000 0x000010000x08000000 0x00001000 0x0A000000 0x000010000x10000000 0x00001000 0x00000004 29.93368 379.5167 Currently active Calibration Parameters part0x00000004 24.35184 23.78 0x00000004 24.37691 16.45607782 59.47631 298.15 003401 179.927 297.1378006804 099747 296.6901 10469 298.3302Special Commands for Calibration with Visical 0x0000003F Calibration StandardsAvailable Sets of Calibration Standards LSB 0x00000001 Set180 Definitions for Individual Sets of Calibration Standards0x0FFF0FFF 0x05540FFF 0x02480FFFNist Standard DINMettler Toledo Radiometer Sensor Status Temperature Ranges168.3667 Operating Hours and CountersCurrently Active Warnings History of WarningsDefinition of Warnings Errors Currently Active ErrorsHistory of Errors Definition of Errors Reading Definition of SIP and CIP SIPCIP 120 130 Reading the Sensor’s Quality IndicatorEPHFI010 Sensor Identification and InformationGeneral Information Sensor IdentificationFree User Memory Space 0001001Freeuserspace 732255 System CommandsRecall Sensor’s Factory Settings Hello WorldPH ARC Sensors Modbus RTU Programmer’s Manual EPHUM011