Hart Interface Devices | Emerson Process Management 3081 pH/ORP

MODEL 3081 pH/ORP	SECTION 15.0
	THEORY - REMOTE COMMUNICATIONS

SECTION 15.0

THEORY - REMOTE COMMUNICATIONS

15.1Overview of HART Communications

15.2HART Interface Devices

15.3AMS Communication

15.1OVERVIEW OF HART COMMUNICATION

HART (highway addressable remote transducer) is a digital communication system in which two frequencies are superimposed on the 4 to 20 mA output signal from the transmitter. A 1200 Hz sine wave represents the digit 1, and a 2400 Hz sine wave represents the digit 0. Because the average value of a sine wave is zero, the digital sig- nal adds no dc component to the analog signal. HART permits digital communication while retaining the analog signal for process control.

The HART protocol, originally developed by Fisher-Rosemount, is now overseen by the independent HART Communication Foundation. The Foundation ensures that all HART devices can communicate with one another. For more information about HART communications, call the HART Communication Foundation at (512) 794-0369. The internet address is http://www.hartcomm.org.

15.2 HART INTERFACE DEVICES

HART communicators allow the user to view measurement data (pH, ORP and temperature), program the transmit- ter, and download information from the transmitter for transfer to a computer for analysis. Downloaded information can also be sent to another HART transmitter. Either a hand-held communicator, such as the Rosemount Model 275, or a computer can be used. HART interface devices operate from any wiring termination point in the 4 - 20 mA loop. A minimum load of 250 ohms must be present between the transmitter and the power supply. See Figure 15-1.

4-20 mA + Digital

250

ohm

Model 3081 pH

Smart

Control System

Transmitter

Hand Held

Communicator

Bridge

(“Configurator”)

Computer

FIGURE 15-1. HART Communicators.

Both the Rosemount Model 275 and a computer can be used to communicate with a HART transmitter. The 250 ohm load (minimum) must be present between the transmit- ter and the power supply.

126

Image 140

Emerson Process Management 3081 pH/ORP Section Theory Remote Communications, Overview of Hart Communication

Contents

Model 3081 pH/ORP Essential Instructions What YOU Need to Know Use the Quick Start Guide if Base ModelRTD Preamplifier located Model Option note Quick Start Guide for Model 3081pH/ORP Output Optional WiringPower up and Calibration Automatic Buffer Calibration Standardizing to Match a Reference Instrument Calibrate Program Diagnose Menu Tree for pH Technical Support Hotline Table of Contents Model 3081 PH/ORP Microprocessor Transmitter Table of Contents CONT’D 13.0 11414.0 120 Table of Contents CONT’D List of Figures Table of Contents CONT’D List of Figures CONT’D Table of Contents CONT’D List of Tables Section Description and SpecificationsFeatures Model 275 Hart COMMUNICATOR. The Model AccessoriesYear 2000 Compliance Millennium Status Specifications -GENERAL for Model 3081 pH/ORP Intrinsic SafetyConduit Openings 3/4 in. Fnpt Hazardous Area Classification Explosion Proof PH Input Range 0 to 14 pH Specifications ORPOrdering Information Model 3081 pH/ORP TRANSMITTER-SENSOR Compatibility Chart Preamplifier LocationSensor-mounted Remote Model ORP MODEL/PN Description Shipping Weight Section Installation PRE-INSTALLATION Setup 2.2.1 Transmitter Default SettingsTemperature Element Unpacking and Inspection Changing Switch and Jumper Positions Preamplifier Location 40308110 Mechanical Installation 2.4.1 General information Orienting the Display Board Mounting on a Flat Surface. See Figure Mounting the Model 3081 pH/ORP Transmitter on a Flat Surface 40308103 Pipe Mounting Power Supply-Current Loop Wiring. Refer to Figure Power SUPPLY/CURRENT LoopPower Supply and Load Requirements. Refer to Figure General Information Section WiringGeneral Information Wiring Diagrams Wiring Diagrams for Model 396R Sensors Junction Box Wiring Diagrams for pH and ORP SensorsWire Function Wiring Diagram Wiring Diagrams for Model 396P Sensors Junction Box Wiring Diagrams for Model 389 Sensors Junction Box Wire Functions Wiring Diagram Wiring Diagrams for Model 385+ Sensors Junction BoxWire Functions Jumpers Supplied by Customer Section Section Section 15. Wire functions for Model 385+ 17. Wire functions for Model 328A-07 19. Wiring diagram for Model 320HP-10-55 21. Wire Functions for Model Section 24. Preparation of Raw Connecting Cable PN Sensor Flow Chart on Sensor Flow Chart on Sensor Flow Chart Section Intrinsically Safe & Explosion Proof Intrinsically Safe InstallationsExplosion Proof Installations Fmrc Installation for Model 3081 pH/ORP Transmitter Page CSA. forInstallation 3081Model TransmitterpH/ORPPage Page I T N E X T T E R Section Operation with Remote ControllerDisplays Infrared Remote Controller IRC KEY Functions Infrared Remote Controller Menu Tree for pH Diagnostic Messages ORP Menu Tree ORP Retrieving a Lost Security Code SecurityEntering the Security Code Connecting the Hart Communicator Operation Section Operation with Model Fast Key Sequences Off-line and On-line OperationMenu Tree Is on 2b. pH Menu Tree Hart 3a. ORP Menu Tree Hart 3b. ORP Menu Tree Hart Entering and Leaving the Calibrate Menu Using the Hold FunctionGeneral Temperature Calibration ProcedurePurpose TEMP AdJ Use of Calibration Standards buffers Auto CalibrationWhat Happens During Auto Calibration? CAL bF 10.00 Manual Calibration 10.00 What Happens During Standardization? Making the Transmitter Reading Match a Second pHMeter Standardization Std Slope Programming for pH Measurements Entering and Leaving the Program Menu PH Settings List Mnemonic Display Limits Factory Settings User Settings Output Ranging Definitions 4MA Diagnostic Parameters Suggested Glass Impedance Warning and Failure Limits Section GFH GwjhGwjl GFL RFH RWJHRWJL RFL Temperature Related Settings TEMP TAUtOTMAn TC 1 Display Units DISPLAYTYPE Code Buffer Calibration Parameters M E BUFFErBAUtO Isopotential Parameters Snr ISOPOtntALTCOEFF 000 TESt Generating a Test CurrentSIM OUtPUt Section Calibration of ORP Measurements TEMP AdJ 25.0 Preparation of ORP Standard Solutions Std Section Programming for ORP Measurements ORP Settings LIst Mnemonic Display Factory User Limits Settings Program Level Output Ranging 20MA 400 Diagnostic Parameters DIAGnOSTIC RWJH Temperature Element Definition Display Units Generating a Test Current Overview Section MaintenanceTransmitter Maintenance PH Sensor Maintenance Frequency of CleaningCleaning Procedures Problem Cleaning Suggestions Checking the Reference Electrode Rejuvenating Reference Electrodes Calibration Frequency ORP Sensor Maintenance 11.4.1 Frequency of CleaningCalibration 11.5.1 General Factory Assistance and Repairs Section TroubleshootingTesting the Transmitter by Simulating pH Message Section Calibration ErrorsTroubleshooting is easy as 1, 2 Troubleshooting Flowchart Glassfail Glassfail Slope Condition of Sensor Troubleshooting Flowchart GLASSWArn Slope Status of SensorGLASSWArn REF Fail Troubleshooting Flowchart rEF Fail Troubleshooting Flowchart rEF WArn Troubleshooting Flowchart- tEMP HI and tEMP LOREFWArn CALIbrAtE Three-wire RTD RTD Resistance Values Temperature 3K Balco Troubleshooting Flowchart- LInE Fail LInE Fail Troubleshooting Flowchart-InPUt WArn InPUt WArn Troubleshooting Flowchart-SLOPE Err LO Slope Err LO Troubleshooting Flowchart-SLOPE Err HI Troubleshooting Flowchart-Std ErrSlope Err HI Std Err Troubleshooting-AdC WArn or CyCLE PWr Troubleshooting-WritE ErrROM Fail or CPU Fail AdC WArn or CyCLE PWr 102 Symptom SectionFACt Fail 12.5.1 Id 000 in Display 103 104 PH Reading in Buffer Drifts During Manual CalibrationSensor Does Not Respond To Known pH Changes 105 Temperature Reading Is Inaccurate Hart Communications ProblemsNo Display Display Segments Missing Replace the display board PN 106 12 .13 Transmitter Locks Up 12 .14 Transmitter Periodically Restarts Itself YES OK? Diagnostic Messages Testing the Transmitter by Simulating the pHDiagnostic Measurements Voltage mV 111 PH Simulation with the Model 381+ Sensor Simulate pH through Model 381+ Sensor Preamplifier 112 Return of Materials PH Simulation When Preamplifier is in SensorTroubleshooting Assistance PH Measurements 115 Measuring ElectrodeReference Electrode Liquid Junction Potential 116 Glass Electrode Slope Buffers and CalibrationTemp C Slope mV/unit pH 117 Junction Potential Mismatch 118 119 Sensor DiagnosticsSHIELDS, INSULATION, and Preamplifiers Section ORP Measurements General Measuring Electrode Reference ElectrodeLiquid Junction Potential 121 122 Relating Cell Voltage to ORP14.6 ORP, CONCENTRATION, and pH 123 Interpreting ORP MeasurementsORP,mV VI,Chromiumppm Sulfur dioxide added Calibration 124 125 Hart Interface Devices Section Theory Remote CommunicationsOverview of Hart Communication Asset Management Solutions AMS Main Menu Tools 127 Section Glossary Term Definition 129 Hart 130 ORP 131 RTD 132 133 Section Return of Material Warranty RepairNON-WARRANTY Repair Warranty Return of Material ON-LINE Ordering NOW Available on OUR WEB Site