Transmitter HC301 Technical information English Version 1.2 * HC301 is a transmitter for pH/mV-measurement * Data range: 0-14pH, ±1000mV, 0-150OC * Single- or dual slope calibration of pH-electrode * Temperature compensation via Pt100 / Pt1000 sensor * Display pH/mV or temperature * Analogue output 0(4) - 20mA for pH/mV or OC * Analogue output may be inverted for use in a control loop * Galvanic insulation between input and I/O (incl. 24V) * Optional: Serial communication via MODbus Features The HC300 Familiy Features Input The Transmitter HC300 Familiy presently consists of the modules: The pH electrode is connected to pin 1-2 on the unit (see figure on page HC300: Datalogger/MODbusmaster w/ dual serial com. 4 analogue inp. 2). The mV signal from the electrode is amplified by a highimpedanse HC301: pH/temp. transmitter with MODbus and 4-20mA output. amplifier before entering the microprocessor. The Pt100/Pt1000 sensor HC302: O2 transmitter with MODbus and 4-20mA output is connected to pin 4-5 on the unit. The measured values are basis for the HC303: Conductivity transmitter with MODbus and 4-20mA output temperature display and compensation performed by the built-in micro- HC304: Transmitter for 4 analogue inputs with MODbus and 4-20mA processor. Pin 3 has no internal connections and may be used as coupling output for a conducter shield. Display Analogue output The HC300 family has a 3 digit display and 6 LEDs for setup and The HC304 Module has an analogue output (0)4-20 mA. Using Setup 0- displaying measured values. The ‘Mode’ key is used to navigate. The 20mA or 4-20mA may be selected. The output is proportional to pH/mV LED marked ‘Com.’ is lit when the MODbus is active. or temperature and is galvanic insulated from the inputs. Programming MODbus (Optional) The module is programmed by the use of 3 keys located on the front Aquired data is transferred using the MODbus standard for multidrop panel. The ‘Mode’ key is used for selecting setup and the ‘Up’ og ‘Down’ communication.. The units are connected using the RS485 system. The keys are used to scroll through the programmable parameters. The para- Modbus-master may be the HC300 ‘Dat’ module or a SCADA system meter to be altered is selected with the ‘Mode’ key and the value is changed with installed software for MODbus. Parameter 02 is used to set the using the ‘Up’ og ‘Down’ keys. Parameter no. 01 is a softwarelock which address of the module to ‘Off’ or 1..247. must be set to ‘Off’ in order to change any parameter. Technical Specifications Mechanical Electrical Housing: Lexan UL94V-0 (Upper part) Power Supply: 24Vdc ±10% Noryl UL94V-0 (Lower part) Consumption: 60 mA max Mounting: M36 for 35 mm DIN rail Sensor: Combination electrode IP Class: Housing IP40. Connector IP20 pH/mV range: 0-14 pH, ±1000mV Connector: Max 16A. Max 2,5 mm2 pH input: < 1pA, >10GΩ Max torque 0,6 Nm Accuracy: ±0,2% Temp.: -15 to +50 °C Temperature sensor: Pt100, Pt1000 Weight: 75 g Temperature range: 0-150°C ± 0,3°C Dimens.: D 58 x W 36 x H 86 mm Temp. compensation: Fixed or via measurement CE mark: EN61326A Analogue output: 0(4)-20mA, max. 250Ω Parameters Function and Programming List of Parameters The 14 progammable parameters are shown in the table to the right. The No Parameter Description Range Default table show Par. no., name, function, programming range and default 01 Lock Software lock On / Off On setting. For access see the paragraph about programming on page 1. If 02 Address Address on the MODbus Off, 1..247 Off the softwarelock (Par. no. 1) is active the parameter setting can be read 03 pH/mV Type of input pH, mV pH 04 Temperature Type of input Pt100, Pt1000 Pt100 but not altered. 05 Compensation Temp. compensation of pH Automatic, fixed Fixed Par. no. 2 is used to set the module’s address for MODbus communi- 06 Comp. temp. Compensating temp. 0..150 25 cation. 07 Cable impedance Impedance of Pt100 cable 0.0 .. 9.9 Ohm 0.0 Par. no. 3 indicates the type of input for the pH/mV input. 08 Dual slope Calibration of pH electrode Off(single), On(dual) Off 09 Range mV Range for mV ±1000, -1000-0, 0-1000 ±1000 Par. no. 4 indicates the type of input for the temperature input. 10 Input for Iout Input for the analoge output pH or temperature pH Par. no. 5. If Par. no. 3 is set to pH, the signal is temperature compensated. 11 Iout Type of output 4-20mA, 0-20mA 4-20 Par. no. 5 is used to set the temperature compensation to either fixed or 12 Iout mode Iout mode non inverted, inverted n.inv based on the measured temperature. 13 Energy save Energy savings functionallity On / Off On 14 Baudrate MODbus baudrate 9.600 / 19.200 19.200 Par. no. 6 is used to set the fixed temperature for compensation of the pH measurement. Par. no. 11 is used to set the analogue output to either 0-20 mA or 4-20 Par. no. 7. If a long cable is used for the Pt100 sensor the serial impedance mA. should be entered and compensated for. Par. no. 12 is used if the output signal has to be inverted i.e. for use in a Par. no. 8 is used to set how the pH electrode may be slope calibrated. If control loop. The resulting output corresponds to 20-0mA or 20-4mA. dual slope (On) is selected, the electrode has to be calibrated at both an Par. no. 13 Energy savings mode. If no keys are pressed for approx. 10 acidic and an alkaline pH. If single-slope (Off) is selected, the calibration min. the display will show a flashing bar. Pressing any key will return to may be performed at either acidic or alkaline pH. normal display. Par. no. 9. If Par.no. 3 is set to mV, the range is set using this parameter. Par. no. 14 The MODbus standard requires a baudrate of 9.600 or It is possible to select the whole range (±1000mV), the negative range (- 19.200, this is set using Par. no.14. The baudrate is set in accordance with 1000-0mV) or the positive range (0-1000mV). This setting has an the MODbus-master. The Master may be the HC300 ‘Dat’ module or a influence on the scaling of the analogue output and the transferred data. SCADA system. Par. no. 10 is used to set the analogue output proportional to either the After setup is completed Par. no. 00 is selected and the ‘Mode’ key is pH/mV signal or the temperature signal. pressed in order to return to the normal display. Buffer/Slope adjustment Typical Installation Calibration of the pH electrode is done via the Up/Down keys on the front. Using the ‘Mode’ key select ‘Buffer’ and calibrate the electrode to pH7 using the Up/Down keys until the display reads 7.00. Next select ‘Slope’ and use the Up/Down keys, until the display reads the desired value. If dual-slope is selected (Parameter 7) the electrode must be calibrated at two points - one above pH7 and one below. All settings are stored in EEProm, so as to remember the values after a power down of the unit. MODbus In order to utilize the MODbus interface the HC301 must be ordered The HC301 contains 2 measurements (pH/mV and temperature). Access with MODbus. to these are gained through the function code Read_Input_Registers (04). Further more the HC301 gives access to different diagnostic values via HC301 may be used as a slave for the ‘Dat’ - unit HC300 or as a slave in Diagnostics (08), as shown in the following. a SCADA system. The setup / communication for each case will be explained in the following. Read_Input_Registers Function code Start address Number of values With HC300 04 1 1 or 2 If HC301 is used together with the HC300, the user must pay attention Value 1 is pH/mV and value 2 is temperature. Please note that the to two things: The baud rate on the MODbus as well as the address of measurements are transmitted in sequence; If 2 values are chosen both the HC301. pH/mV and temperature are transmitted. If for instance the value for The baud rate (P14) must be set to the baud rate of the HC300. Whether temperature is wanted, 2 values must be requested. Both values are rated a baud rate of 19.200 or 9.600 is used is of no importance, as long as all to 0-1000 corresponding to the range, but the temperature has an offset units on the MODbus are set to the same baud rate. of 1024; I.e. 0-14pH is transmitted as 0-1000 and 0-150OC as 1024- The address (P02) must be unique in the network; Two units are not 2024. The start address is of no importance - only the number of values allowed to have the same address. In a network with the HC300 as the determines the returned values. master, all addresses must be assigned without leaving any address out; i.e. if 3 units are connected to an HC300, the addresses 1, 2 & 3 must be Diagnostics assigned to the three units. The order of the addresses is of no impor- Function code Sub code (HEX) Description tance. In a network with an HC300, up to 14 slaves may be connected, 08 00 Return Query Data allowing only the addresses 1..14.