Emerson 848T manual RTD or Ohm Inputs, Thermocouple or Millivolt Inputs, Analog Inputs

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Reference Manual

00809-0100-4697, Rev EA October 2011

Rosemount 848T

RTD or Ohm Inputs

Various RTD configurations, including 2-wire and 3-wire are used in industrial applications. If the transmitter is mounted remotely from a 3-wire RTD, it will operate within specifications, without recalibration, for lead wire resistances of up to 60 ohms per lead (equivalent to 6,000 feet of 20 AWG wire). If using a

2-wire RTD, both RTD leads are in series with the sensor element, so errors can occur if the lead lengths exceed one foot of 20 AWG wire. Compensation for this error is provided when using 3-wire RTDs.

Thermocouple or Millivolt Inputs

Use appropriate thermocouple extension wire to connect the thermocouple to the transmitter. Make connections for millivolt inputs using copper wire. Use shielding for long runs of wire.

Analog Inputs

The analog connector converts the 4–20 mA signal to a 20–100 mV signal that can be read by the 848T and transmitted using FOUNDATION fieldbus.

Use the following steps when installing the 848T with the analog connector:

1.The 848T, when ordered with option code S002, comes with four analog connectors. Replace the standard connector with the analog connector on the desired channels.

2.Wire one or two analog transmitters to the analog connector according to Figure 2-5.There is space available on the analog connector label for identification of the analog inputs.

NOTE

Power supply should be rated to support the connected transmitter(s).

3.If the analog transmitters can communicate using HART protocol, the analog connectors are supplied with the ability to switch in a 250 ohm resistor for HART communication (see Figure 2-6).

One switch is supplied for each input (top switch for “A” inputs and bottom switch for “B” inputs). Setting the switch in the “ON” position (to the right) bypasses the 250 ohm resistor. Terminals are provided for each analog input to connect a Field Communicator for local configuration.

2-5

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Contents 00809-0100-4697, Rev EA October Reference ManualPage Customer Central National Response Center International Rosemount 848T High Density Temperature Transmitter withPage Table of Contents TOC-2 Operation MaintenanceSection Appendix aElectrical shock could cause death or serious injury Safety MessagesSection Introduction Process leaks could result in death or serious injuryTransmitter Fieldbus host or configuration toolMaintenance of the Rosemount 848T Temperature Transmitter OverviewService Support Rosemount 848T Safety Messages Mounting Section InstallationMounting to a Panel with a Junction Box Mounting to a DIN Rail Without an EnclosureAluminum/Plastic Junction Box Stainless Steel Junction Box Mounting to a 2-in. Pipe StandLeads and terminals WiringSpur Signal Wiring Devices 1 through ConnectionsRTD or Ohm Inputs Thermocouple or Millivolt InputsAnalog Inputs Analog Input ConnectorsPower Supply Ohm resistor in the loop when switched to the leftPower Supply Surges/TransientsConnections Grounding Shielded WireFieldbus bus 848T Power Supply Sensor Wires Shield ground pointsTransmitter Enclosure optional MA loopSecurity SwitchesSimulate Enable Switch is not functionalSensor Tag TaggingCommissioning Tag Transmitter TagInstallation Using Cable GlandsUsing Conduit Entries Section Configuration Configuration Transmitter Configuration Custom Configuration MethodsStandard Rosemount 848T Block Common Configurations for High Density ApplicationsTypical Profiling Application FunctionMonitoring Application with a Single Selection Measuring Temperature Points IndividuallyMultiple Analog Input or Analog Input Block Configuration Block Configuration Resource BlockNumber Parameter Description 00809-0100-4697, Rev EA October Resource Block Parameters Failedenable SaveconfignowSaveconfigblocks StartwithdefaultsBlock is processing its normal background memory checks Block ErrorsModes Automatic AutoStatus Handling Out of Service OOSAlarm Detection PlantWeb AlertsFailedmask 00809-0100-4697, Rev EA October Failure AlarmsMaintenance Alarms/Priority Alarm Advisory AlarmsAlarm Recommended Actions for PlantWeb Alerts Alarm Type Active Event Recommended ActionTransducer Blocks RESOURCE.HARDWAREREV,RESOURCE.RBSFTWRREVALL Channel Description Transducer Block ErrorsTransducer Block Channel Definitions Channel Definitions for the 848TBlock outputs reflect the analog input measurement 00809-0100-4697, Rev EA October Block/Transducer ErrorTransducer Block Alarm Detection Transducer Block ModesSENSOR4CONFIG SENSOR1CONFIGSENSOR2CONFIG SENSOR3CONFIGChanging the Sensor Configuration in the Transducer Block 11. Xderror Sub-Parameter Structure 12. Sensorconfig Sub-Parameter StructureTransducer Block Sub-Parameter Tables 16. Transducer Status Sub-Parameter Structure 13. Sensorstatus Sub-Parameter Structure14. Sensorcal Sub-Parameter Structure 15. Calstatus StructureStructure Dual Sensor Status TableStructure 20. Validation Config Sub-Parameter Structure Sensor Calibration in the Sensor Transducer BlockStructure Parameter Description Rosemount 848T Operation and Maintenance Foundation Fieldbus InformationFoundation Commissioning Addressing Restart Processor cycling Hardware MaintenanceRestart with Defaults Sensor CheckSymptom Possible Causes Corrective Action TroubleshootingTransducer Block Troubleshooting Symptom Possible Cause Corrective ActionAppendix a Reference Data Functional SpecificationsTransient Protection Update TimeAlarms Backup Link Active Scheduler LASPhysical Specifications Function Blocks Performance SpecificationsInput Ranges Sensor Option Sensor Reference 3-Wire RTDsAccuracy for Differential Configurations AccuracyAnalog Sensors 4-20mA Sensor Option Alarm Levels AccuracyAmbient Temperature Effect Top View Dimensional DrawingsAmbient Temperature Notes Examples Rosemount 848TStainless Steel Junction Box-Cable Gland option code JS2 Side View Front ViewFront View Side View Side View Stainless Steel Junction Box-Conduit Entry option code JS3Front View Side View Mounting OptionsAluminum/Plastic Junction Box Styles JA and JP Stainless Steel Junction Box Style JSOptions Ordering InformationEnclosure Options Standard Software Configuration StandardSpecial Temperature Test Expanded Conduit Electrical Connector StandardRosemount 848T North American Approvals Table B-2. Entity Parameters for Non Incendive Field WiringAppendix B Product Certificates Hazardous Locations CertificatesPower/Bus Canadian Standards Association CSA Certifications Special Conditions for Safe Use Power/Bus SensorEuropean Approvals Atex CertificationsCi = Li = Rosemount 848T IECEx Certifications Special Conditions of Safe UseRosemount 848T China NEPSICertifications Parameters Terminals of power/loopJapanese Certifications Intrinsically Safe and NON-INCENDIVE Installations Installation Drawings Figure B-1. FM Intrinsic Safety/ Fisco 00809-0100-4697, Rev EA Rosemount 848T Figure B-2. CSA Intrinsic Safety/ Fisco Rosemount 848T Rosemount 848T Overview Function Blocks Appendix C Foundation fieldbus TechnologyLinkages Status InputOutput SnapTransducer Blocks Device Descriptions Block OperationInstrument- Specific Function Blocks Alerts Resource BlocksNetwork Communication Link Active Scheduler LASFieldbus Link MID x ST Data LAS ParametersReport Distribution Backup LASAddressing Scheduled Transfers Publisher/SubscriberUnscheduled Transfers ScheduleDevice Device Y Device Z Function Block Scheduling OUT Appendix D Function BlocksAnalog Input AI Function Block Number Parameter Units DescriptionIoopts AlarmhysXdscale Outscale63% of Change OUT mode in manOUT mode in auto FunctionalitySimulationIndirect Signal ConversionFiltering DirectConditions Indirect Square RootTable D-3. Alarm Priority Levels Manual ManValue of the block output OUT may be set manually Uncertain if Limited Uncertain if in Manual modeAdvanced Features BAD if LimitedHIHILIMIT, Lolimit AI Block TroubleshootingApplication Information XdblockTable D-4. Multiple Analog Input Function Block Parameters Multiple Analog Input MAI Function BlockCAPSTDDEV1 Simulate Figure D-4. Multiple Analog Input Function Block SchematicOption in Manual or Out of Service mode only Devices such as flowmetersTable D-5. Blockerr Conditions Block output OUT may be set manually MAI Block Troubleshooting OUT Outrange Input Selector Function BlockTable D-6. Input Selector Function Block Parameters IN1 IN2 IN3 IN4 IN5 IN6 IN7Opselect SelecttypeMingood SelectedFunctionality INn DISABLEnMode Logic Selection Alarm OUTOUT reflects the selected value Table D-8. Alarm Priority LevelsUse Uncertain as Good Block ExecutionIsel Block Troubleshooting Numerics IndexErrors Modes Automatic Configuration Errors Modes AutomaticMaintalarms Troubleshooting Alarm DetectionPage Pacific Private Limited Rosemount Inc

848T specifications

The Emerson 848T is a state-of-the-art temperature transmitter designed for accurate and reliable temperature measurement in various industrial applications. This device has gained recognition for its advanced features and robust performance, making it a popular choice among engineers and technicians in the field.

One of the key highlights of the Emerson 848T is its unique dual-channel capability, which allows it to seamlessly monitor two temperature sources simultaneously. This functionality is particularly beneficial in processes where multiple temperature points need to be assessed, optimizing efficiency and reducing the need for additional equipment. It supports various sensor types, including thermocouples, RTDs, and resistance temperature detectors, making it versatile for different applications.

The 848T is equipped with sophisticated digital processing technology, which enhances its accuracy and stability. It features a 24-bit analog-to-digital converter, ensuring precise measurement and minimizing drift over time. Moreover, the device boasts a wide operating temperature range, accommodating ambient conditions from -40°C to 85°C. This durability makes it suitable for harsh environments commonly encountered in industries such as oil and gas, pharmaceuticals, and power generation.

Another significant characteristic of the Emerson 848T is its configurable output options. Users can choose from a range of output signals, including 4-20 mA, which provides a standard interface for integration into existing control systems. Additionally, it offers a HART communication protocol, allowing for easy configuration, calibration, and diagnostics through a digital interface. This feature enhances the transmitter's usability, enabling operators to perform adjustments without direct access to the device.

The device is designed with user-friendliness in mind. Its intuitive setup procedure and robust graphical user interface simplify the commissioning process, ensuring that even those new to the technology can easily navigate the system. An integrated LCD display provides real-time readings and status information, facilitating monitoring at a glance.

In summary, the Emerson 848T temperature transmitter combines reliable performance, user-friendly design, and advanced digital technologies. Its dual-channel capability, wide sensor compatibility, and adjustable output options make it an essential tool for achieving precise temperature measurements in various industrial settings. With these compelling features, the Emerson 848T stands out as a leading choice for professionals seeking accuracy and efficiency in their temperature monitoring applications.
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