Emerson 848T Addressing Scheduled Transfers, Backup LAS, Publisher/Subscriber, Client/Server

Page 88

Rosemount 848T

Reference Manual

00809-0100-4697, Rev EA October 2011

Backup LAS

Addressing

Scheduled Transfers

A LM device is one that has the ability to control the communications on the bus. The LAS is the LM capable device that is currently in control of the bus. While there can be many LM devices acting as backups, there can only be one LAS. The LAS is typically a host system but for stand-alone applications, a device may be providing the role of primary LAS.

To setup, configure, and communicate with other devices on a segment, a device must be assigned a permanent address. Unless requested otherwise, it is assigned a temporary address when shipped from the factory.

FOUNDATION fieldbus uses addresses between 0 and 255. Addresses 0 through 15 are reserved for group addressing and for use by the data link layer.

If there are two or more devices on a segment with the same address, the first device to start up will use the assigned address. Each of the other devices will be given one of the four temporary addresses. If a temporary address is not available, the device will be unavailable until a temporary address is available.

Use the host system documentation to commission a device and assign a permanent address.

Information is transferred between devices over the FOUNDATION fieldbus using three different types of reporting.

Publisher/Subscriber

This type of reporting is used to transfer critical process loop data, such as the process variable. The data producers (publishers) post the data in a buffer that is transmitted to the subscriber, when the publisher receives the Compel Data (CD). The buffer contains only one copy of the data. New data completely overwrites previous data. Updates to published data are transferred simultaneously to all subscribers in a single broadcast. Transfers of this type can be scheduled on a precisely periodic basis.

Report Distribution

This type of reporting is used to broadcast and multicast event and trend reports. The destination address may be predefined so that all reports are sent to the same address, or it may be provided separately with each report. Transfers of this type are queued. They are delivered to the receivers in the order transmitted, although there may be gaps due to corrupted transfers. These transfers are unscheduled and occur between scheduled transfers at a given priority.

Client/Server

This type of reporting is used for request/response exchanges between pairs of devices. Like Report Distribution reporting, the transfers are queued, unscheduled, and prioritized. Queued means the messages are sent and received in the order submitted for transmission, according to their priority, without overwriting previous messages. However, unlike Report Distribution, these transfers are flow controlled and employ a retransmission procedure to recover from corrupted transfers.

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Contents Reference Manual 00809-0100-4697, Rev EA OctoberPage Rosemount 848T High Density Temperature Transmitter with Customer Central National Response Center InternationalPage Table of Contents Operation Maintenance SectionAppendix a TOC-2Safety Messages Section IntroductionProcess leaks could result in death or serious injury Electrical shock could cause death or serious injuryFieldbus host or configuration tool Maintenance of the Rosemount 848T Temperature TransmitterOverview TransmitterService Support Rosemount 848T Section Installation Safety Messages MountingMounting to a DIN Rail Without an Enclosure Mounting to a Panel with a Junction BoxMounting to a 2-in. Pipe Stand Aluminum/Plastic Junction Box Stainless Steel Junction BoxWiring Spur Signal Wiring Devices 1 throughConnections Leads and terminalsThermocouple or Millivolt Inputs RTD or Ohm InputsAnalog Inputs Connectors Power SupplyOhm resistor in the loop when switched to the left Analog InputSurges/Transients Power SupplyConnections Shielded Wire Grounding848T Power Supply Sensor Wires Shield ground points Transmitter Enclosure optionalMA loop Fieldbus busSwitches Simulate EnableSwitch is not functional SecurityTagging Commissioning TagTransmitter Tag Sensor TagUsing Cable Glands InstallationUsing Conduit Entries Section Configuration Transmitter Configuration Custom Configuration Methods ConfigurationStandard Rosemount 848T Common Configurations for High Density Applications Typical Profiling ApplicationFunction BlockMeasuring Temperature Points Individually Monitoring Application with a Single SelectionMultiple Analog Input or Analog Input Block Configuration Resource Block Block ConfigurationNumber Parameter Description 00809-0100-4697, Rev EA October Resource Block Parameters Saveconfignow SaveconfigblocksStartwithdefaults FailedenableBlock Errors ModesAutomatic Auto Block is processing its normal background memory checksOut of Service OOS Alarm DetectionPlantWeb Alerts Status Handling00809-0100-4697, Rev EA October Failure Alarms FailedmaskAdvisory Alarms Maintenance Alarms/Priority AlarmAlarm Alarm Type Active Event Recommended Action Recommended Actions for PlantWeb AlertsRESOURCE.HARDWAREREV, Transducer BlocksRESOURCE.RBSFTWRREVALL Transducer Block Errors Transducer Block Channel DefinitionsChannel Definitions for the 848T Channel Description00809-0100-4697, Rev EA October Block/Transducer Error Transducer Block Alarm DetectionTransducer Block Modes Block outputs reflect the analog input measurementSENSOR1CONFIG SENSOR2CONFIGSENSOR3CONFIG SENSOR4CONFIGChanging the Sensor Configuration in the Transducer Block 12. Sensorconfig Sub-Parameter Structure 11. Xderror Sub-Parameter StructureTransducer Block Sub-Parameter Tables 13. Sensorstatus Sub-Parameter Structure 14. Sensorcal Sub-Parameter Structure15. Calstatus Structure 16. Transducer Status Sub-Parameter StructureDual Sensor Status Table StructureStructure Sensor Calibration in the Sensor Transducer Block 20. Validation Config Sub-Parameter StructureStructure Parameter Description Rosemount 848T Foundation Fieldbus Information Operation and MaintenanceFoundation Commissioning Addressing Hardware Maintenance Restart with DefaultsSensor Check Restart Processor cyclingTroubleshooting Transducer Block TroubleshootingSymptom Possible Cause Corrective Action Symptom Possible Causes Corrective ActionFunctional Specifications Appendix a Reference DataUpdate Time AlarmsBackup Link Active Scheduler LAS Transient ProtectionPhysical Specifications Performance Specifications Function BlocksSensor Option Sensor Reference 3-Wire RTDs Accuracy for Differential ConfigurationsAccuracy Input RangesSensor Option Alarm Levels Accuracy Analog Sensors 4-20mAAmbient Temperature Effect Dimensional Drawings Ambient Temperature Notes ExamplesRosemount 848T Top ViewSide View Front View Stainless Steel Junction Box-Cable Gland option code JS2Front View Side View Stainless Steel Junction Box-Conduit Entry option code JS3 Side ViewMounting Options Aluminum/Plastic Junction Box Styles JA and JPStainless Steel Junction Box Style JS Front View Side ViewOrdering Information OptionsSoftware Configuration Standard Special Temperature Test ExpandedConduit Electrical Connector Standard Enclosure Options StandardRosemount 848T Table B-2. Entity Parameters for Non Incendive Field Wiring Appendix B Product CertificatesHazardous Locations Certificates North American ApprovalsPower/Bus Canadian Standards Association CSA Certifications Power/Bus Sensor European ApprovalsAtex Certifications Special Conditions for Safe UseCi = Li = Rosemount 848T Special Conditions of Safe Use IECEx CertificationsRosemount 848T Parameters Terminals of power/loop China NEPSICertificationsJapanese 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 Appendix C Foundation fieldbus Technology Overview Function BlocksInput OutputSnap Linkages StatusDevice Descriptions Block Operation Instrument- Specific Function Blocks AlertsResource Blocks Transducer BlocksLink Active Scheduler LAS Network CommunicationFieldbus Link LAS Parameters MID x ST DataBackup LAS Addressing Scheduled TransfersPublisher/Subscriber Report DistributionSchedule Unscheduled TransfersDevice Device Y Device Z Function Block Scheduling Appendix D Function Blocks Analog Input AI Function BlockNumber Parameter Units Description OUTAlarmhys XdscaleOutscale IooptsOUT mode in man OUT mode in autoFunctionalitySimulation 63% of ChangeSignal Conversion FilteringDirect IndirectIndirect Square Root ConditionsManual Man Table D-3. Alarm Priority LevelsValue of the block output OUT may be set manually Uncertain if in Manual mode Advanced FeaturesBAD if Limited Uncertain if LimitedAI Block Troubleshooting Application InformationXdblock HIHILIMIT, LolimitMultiple Analog Input MAI Function Block Table D-4. Multiple Analog Input Function Block ParametersCAPSTDDEV1 Figure D-4. Multiple Analog Input Function Block Schematic SimulateDevices such as flowmeters Option in Manual or Out of Service mode onlyTable D-5. Blockerr Conditions Block output OUT may be set manually MAI Block Troubleshooting Input Selector Function Block Table D-6. Input Selector Function Block ParametersIN1 IN2 IN3 IN4 IN5 IN6 IN7 OUT OutrangeSelecttype MingoodSelected OpselectINn DISABLEn Mode Logic SelectionAlarm OUT FunctionalityTable D-8. Alarm Priority Levels OUT reflects the selected valueBlock Execution Use Uncertain as GoodIsel Block Troubleshooting Index NumericsConfiguration Errors Modes Automatic Maintalarms TroubleshootingAlarm Detection Errors Modes AutomaticPage Rosemount Inc Pacific Private Limited

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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