A LaymanA Laymans Guide to HARTs Guide to HART Communications with Communications with FIELDVUEFIELDVUE InstrumentsInstrumentsJ eff VonAhnenRick OsbornFIELDVUE Technical SupportEmerson Process ManagementFisher Valve DivisionMarshalltown, IowaPage 2PresentersPresentersJeff VonAhnenFIELDVUE Technical SupportRick OsbornFIELDVUE Technical SupportPage 3Digitally Communicating FIELDVUE Digital Valve ControllersDigitally Communicating Digitally Communicating FIELDVUE Digital Valve ControllersFIELDVUE Digital Valve Controllers Accurately control the valve Accurately control the valve Transmit device health Transmit device health Predict future valve performance Predict future valve performancePage 4FIELDVUE Instruments Designed for DiagnosticsFIELDVUE Instruments FIELDVUE Instruments Designed for DiagnosticsDesigned for DiagnosticsActual Valve TravelInput currentI/P Drive CurrentRelay positionPort B pressurePort A pressureSupply pressure32 Device Alert andStatus indicatorsDrive SignalCycle CounterTravel AccumulatorTriggered PD ProfilePage 5Vast Array of Diagnostics Available Vast Array of Diagnostics AvailableVast Array of Diagnostics AvailableIncreasing Diagnostic CapabilityAlert EventRecord(on-line)(alert events)Network Alert Scan(on-line)(alert log & trending)Performance Diagnostics(on-line)(graphs, interpretation)Dynamic Scan Diagnostics(off-line)(graphs, interpretation)Page 6But it all breaks down if you have HART Communications issues!But it all breaks down if you have But it all breaks down if you have HART Communications issues!HART Communications issues!F1 F2 F3 F4DVC6000: HART TagDevice DisconnectedRETRY QUITWhat causes such problems?What causes such problems?What can be done?What can be done?F1 F2 F3 F4DVC6000: HART TagAccess RestrictedInstrument was takenOut of Service byanother master.ABORTOKPage 7Topics to be discussed: Topics to be discussed:Topics to be discussed: What is HART? Request ResponseHART communications with Primary and Secondary masters. Burst mode communications. Multiple HART masters and communication arbitration. What happens when things go wrong. Techniques for sorting out the problems. What are HART Filters? Review of HART multiplexers and how their differences can affect HART communications.Page 8So, what is So, what is HARTHART??Page 9According to the HARTCommunication Foundation Website:According to the HARTAccording to the HART Communication Foundation Website:Communication Foundation Website:HART: is a master-slave field communications protocol was developed in the late 1980's to facilitate communication with Smart field devices. is an acronym for Highway Addressable Remote Transducer. makes use of the Bell 202 Frequency Shift Keying (FSK) standard to superimpose digital communication signals at a low level on top of the 4-20mA, enabling two-way field communication to take place and makes it possible for additional information beyond just the normal process variable to be communicated to/from a smart field instrument. communicates at 1200 bps without interrupting the 4-20mA signal allows a host application (master) to get two or more digital updates per second from a field device. due to the phase continuous digital FSK signal is phase continuous, creates no interference with the 4-20mA signal. Page 10Overload! Overload! Overload! Overload!Overload! Overload!OK, lets slow it down a bit Page 11HART HART Physical LayerPhysical Layer--the electrical signalsthe electrical signalsPage 12First, what is Analog Control ? First, what is First, what is Analog ControlAnalog Control?? Milliamp control signal created by an Analog Output channel. 4 to 20 milliamps represented 0% to 100%. Referenced relative to constant groundsignal. Used to power coil of wireI/P valve instruments. Goal for Analog Output cards is to generate an accurate, smooth, steady, ripple-free signal.4.08.012.016.020.00.0Page 13What is HART communication? What is What is HARTHARTcommunication?communication? A way to superimpose a digital communication sinusoidal signal onto the milliamp control signal. The same basic technology a phone modem uses to superimpose a digital communications onto an analog phone signal. The milliamp control signal is not affected by the bi-directional digital HART signal.(FYI: HART signals as viewed on an electrical oscilloscope)Page 14What is HART communication? What is What is HARTHARTcommunication?communication? A different waveform for a transmitter on an Analog Input channel compared to a digital valve controller on an Analog Output channel. Depends on what the 1000 pound gorillais for each kind of channel.Page 15What is HART communication? What is What is HARTHARTcommunication?communication? For an Analog Input (AI) channel, the system provides the 24 volt signal (its 1000 pound gorilla) and the transmitter controls the milliamp current signal. So for a transmitter on an AI channel, the HART waveform is modulation of the milliamp current signal.Analog mASignal2200 Hz1200 Hz"1" "0"+0.5 mA- 0.5 mAPage 16What is HART communication? What is What is HARTHARTcommunication?communication? For an Analog Output (AO) channel, the system provides the 4-20 mA control signal (its 1000 pound gorilla) and the digital valve controller controls the voltage on the loop. For a digital valve controller on an AO channel, the HART waveform is modulation of the loop voltage.TerminalVoltage2200 Hz1200 Hz"1" "0"+0.5 VDC- 0.5 VDCPage 17HART CommunicationsHART Communications--Possible Physical Layer Possible Physical Layer problemsproblemsPage 18Electricity compared to water Electricity compared to waterElectricity compared to water A handy way to think about voltageand currentis to compare them to water coming out of a hose. The pressure pushing the water out of the hose is analogous to voltage. The volume of water coming out of hose is analogous to current. It is easy to push a little volume of water out with high pressure (squirt gun). It is hard to maintain high pressure when you are pushing out large volumes of water (fire hose).volume(current)Pressure(voltage)Page 19FIELDVUE Compliance Voltage FIELDVUE Compliance VoltageFIELDVUE Compliance VoltageRequired Compliance Voltage DVC5000 w/ HART: 12.0Vw/o HART: 11.5V DVC6000 w/ HART: 11.0Vw/o HART: 10.5V DVC2000 w/ HART: 9.0Vw/o HART: 8.5VMeasurable Terminal Voltage (typical) DVC5000 @4mA: 10.8V@20mA: 11.0V DVC6000 @4mA: 9.5V@20mA:10.3V DVC2000 @4mA: 8.0V@20mA:8.3VThe DVC takes the available system loop voltage and regulates it down to the Terminal Voltage values.Page 20Insufficient Compliance Voltage can render the HART signal unreadableInsufficient Compliance Voltage can Insufficient Compliance Voltage can render the HART signal unreadablerender the HART signal unreadable4.0 mA 20.0 mA9.55 0.15 V10.35 0.15 V11.0 V minimumfor DVC6000System Compliance Voltagewith HART communicationsAvailable System Compliance VoltageMeasurableTerminalVoltage11.0 V For a FIELDVUE instrument, the available loop compliance voltage needs to be at least 0.5 volts above what is needed for the DVCs terminal voltage. If the voltage droops below this level, the top half of the HART waveform will get clipped offand HART communication faults will occur. Page 21Electrical noise can mess upthe HART signalsElectrical noise can mess upElectrical noise can mess upthe HART signalsthe HART signalsThis includes: High strength Electro-Magnetic Interference (EMI) (walkie talkie, arc welding, etc). Poor electrical wiring, shielding, and grounding practices.Page 22 Non-HART compatible AO channels may view the HART waveform as noiseor AC rippleand may attenuate it down below size of a valid HART signal. To keep the AO channel from reacting to the HART signal, a HF300-series HART Filter may be needed.The host DCS can mess upthe HART signalThe host DCS can mess upThe host DCS can mess upthe HART signalthe HART signalTerminalVoltage2200 Hz1200 Hz"1" "0"+0.5 VDC- 0.5 VDCPage 23What is a HART Filter ? What is a What is a HART FilterHART Filter?? Possibly misnameddoes not do filteringas you would normally expect from an electrical filter circuit. Acts like a wallto block HART signals. HART signals existing on the fieldsideof the HART filter cannot be seen on the systemside.Page 24Troubleshooting hint:You can hear HART signals!Troubleshooting hint:Troubleshooting hint:You can hear HART signals!You can hear HART signals! At frequencies of 1200 and 2200 Hz, HART is in the audible range for the human ear. With a simple speaker / amplifier and a connection cable, you can eavesdrop on HART traffic. Once you are familiar with recognizing the sounds of different kinds of HART signals, this can be a handy troubleshooting tool.Page 25HART CommunicationsHART Communications--Master Communication DevicesMaster Communication DevicesPage 26HART is Question Answer HART is HART is Question Question AnswerAnswer A masterHART device asks a question to the slavefield device. The slavefield device immediately answers this question. The slavedevice does not speak unless spoken to.Page 27HART supports two masters talking to one slave device at the same timeHART supports two masters talking to HART supports two masters talking to one slave device at the same timeone slave device at the same time One master is deemed Primary. Other master is deemed Secondary. Although both masters hear all replies from the slave device, they only respond to the reply directed at them individually. PrimarySecondaryPage 28HART supports two masters talking to one slave device at the same timeHART supports two masters talking to HART supports two masters talking to one slave device at the same timeone slave device at the same timeRules of HART communication arbitration: Only one HART master of each gender allowed. Both masters are very polite and courteous. They alternate taking turns talking to the one slave device. No interrupting while the other master is talking!Page 29There is a third way Burst Mode There is a third wayThere is a third wayBurst ModeBurst Mode A slave device can be configured to provide an answerwithout having been asked a question. When in Burst Mode, the slave device replies with the answer to a predetermined HART command (usually Hart Command 3). This message is an unaddressed broadcast on the loop to any device who listens for such things (like a Tri-LoopHART-to-Analog converter). Page 30Burst Mode Communications Burst Mode CommunicationsBurst Mode Communications Other masters ignore Burst Modemessages, but must arbitrate around them. Burst Mode communications get interspersed between Primary and Secondary master communications. The slave device now becomes responsible for its portion of the HART communication arbitration with the other master devices.Page 31HART Command Arbitration HART Command ArbitrationHART Command Arbitration The smooth interlacing of HART requests and slave replies to avoid collisionsor interruptions. It is the responsibility of every device that wants to contribute in a HART conversation. Usually it is done by master devices, but is also done by a slave device in Burst Mode. Follows the cadence:Primary master (question / answer)Burst Secondary master (question / answer)BurstPage 32HART Communication Rate HART Communication RateHART Communication RateIt takes about second for one HART message:(single master shown)Page 33HART CommunicationsHART Communications--HART CommandsHART CommandsPage 34Typical HART commands Typical HART commandsTypical HART commandsHART commands come in three categories: Universal commands Implemented by ALL HART field devices Commands #0 through #32 Common Practice commands Implemented by many, but not all HART field devices Commands #33 through #127 Device Specific commands Unique to a particular field device Commands #128 and up Same command number will mean different things to different field devices.Page 35Universal HART commands(as defined for a FIELDVUE Instrument)Universal HART commandsUniversal HART commands(as defined for a FIELDVUE Instrument) (as defined for a FIELDVUE Instrument)#0 - Read Unique Identifier#1 - Read Primary Variable#2 - Read Loop Current and Percent of Range#3 - Read Loop Current and four Dynamic Variables#6 - Write Polling Address#11 - Read Unique Identifier associated with a Tag#12 - Read 32-character Message#13 - Read 8-character Tag, 16-character Descriptor, and Date#17 - Write 32-character Message#18 - Write 8-character Tag, 16-character Descriptor, and DatePage 36Common Use HART commands(as defined for a FIELDVUE Instrument)Common Use HART commandsCommon Use HART commands(as defined for a FIELDVUE Instrument) (as defined for a FIELDVUE Instrument)#33 - Read Four Transmitter Slot Variables#35 - Write Primary Variable Range Values#38 - Reset Configuration Change Flag#42 - Master Reset#44 - Change PV Units Code#48 - Read Additional Status#59 - Write Number of Response Preambles#108 - Write Burst Mode Command number#109 - Burst Mode ControlPage 37Device Specific Commands Device Specific CommandsDevice Specific Commands Not listed here - they are Proprietary. Allows for product uniqueness within an Opencommunication protocol. Used for special device functionality (diagnostics, etc.).Page 38Format for various HART commands:Master/Slave/Burst address command byte count status data checksumCommand 3M 93 03 32 36 02 3 017S D3 03 32 36 02 3 26 00 40 40 80 60 00 27 40 80 60 00 39 C1 B7 E0 00 06 C2 DC 80 00 39 BD 7A 00 00E7Command 33M93 03 32 36 02 33 4 0C 00 00 00 3DS 93 03 32 36 02 332600 48 0C 00 00 00 00 03 00 27 40 80 60 00 00 27 40 80 60 00 00 27 40 80 60 00EBCommand 48m 13 03 32 36 02 48 0 A4s 53 03 32 36 02 48 10 00 40 00 00 08 00 02 00 13 67D4Command 0m13 03 32 36 02 0 0 94s 13 03 32 36 02 0 1400 40 FE 13 03 05 05 01 05 08 00 32 36 023APV SV TV QVExample HART Commands Example HART CommandsExample HART Commands1stSlotVariable2ndSlotVariable3rdSlotVariable4thSlotVariablePage 39Device Status byteDevice Status byte Device Status byte Available with every HART reply message:Bit 7 - Field Device Malfunction (hardware error or failure)Bit 6 - Configuration ChangedBit 5 - Cold Power-up (cleared by the 1st HART command)Bit 4 - More Status AvailableBit 3 - Analog Input Fixed (set if DVC is OOS or in Digital Mode)Bit 2 - not usedBit 1 - Internal Sensor Out of Limits (travel, pressure, ortemperature sensors reading beyond their limits)Bit 0 - Variable Out of Range (Primary Variable loop currentout of -25% to +125% range)Page 40HART Command 0 HART Command 0HART Command 0 Hello, who are you? Used by a HART master to match a newly found field device with its proper DD file.(preamble, address stuff) 13 03 05 05 01 05 08 00 32 36 02 (checksum stuff) Manufacturer (i.e. code for Fisher Controls) Device type (i.e. code for DVC6000) Number of preambles (always 5 for a FIELDVUE) Universal Revision (always 5 for a FIELDVUE) Device Revision (DD version) Software Revision (PWB Firmware version) Hardware Revision (encoded PWB Hardware version) Device function flags (always $00 for a FIELDVUE) Device ID number (unique ID number for each FIELDVUE) Page 41Right mouse clickon HART tagfor context menuChoose Communications LogAvailable user tool:ValveLinks Communication LogAvailable user tool:Available user tool:ValveLinkValveLinkssCommunication LogCommunication LogPage 42Running log of HART commands sent between ValveLink and DVCRunning log of HART commands Running log of HART commands sent between ValveLink and DVCsent between ValveLink and DVCNewest...OldestFull detailsof highlightedcommandCan be reviewed or exported and saved as a file. Page 43HART CommunicationsHART Communications--Communication ErrorsCommunication ErrorsPage 44HART Communications errors HART Communications errorsHART Communications errorsF1 F2 F3 F4DVC6000: HART TagDevice DisconnectedRETRY QUITF1 F2 F3 F4DVC6000: HART TagAccess RestrictedInstrument was takenOut of Service byanother master.ABORTOKPage 45What happens when things go wrong? What happens when things go wrong?What happens when things go wrong?You can get HART Communication Errorswhen: Two masters of the same gendertalk at the same time on one loop. A host which doesnt arbitrate between multiple masters very well. Electrical noise messes up the HART signal.Unfortunately, its hard to tell these apart!Page 46Two masters of the same gendertalking at the same timeTwo masters of the same Two masters of the same gendergendertalking at the same timetalking at the same timeYou manually have to separate them: Hosts with HART AO are ALWAYS Primary master. 275 and 375 handheld HART Communicators are ALWAYS Secondary Master. PC programs like AMS Device Manageror AMS ValveLink VL2000 Soloor the Moore IndustriesHIMcan be either master, so they are the candidates to be moved out of the way. BUTthere can only be ONE of any gender.Page 47A host which doesnt arbitrate between multiple masters very wellA host which doesnA host which doesnt arbitrate t arbitrate between multiple masters very wellbetween multiple masters very well Ouch! Most notable when things that work OK separately do not work when connected together with a host system. Usually the best solution is to limit HART applications to just a single master (usually the host Primary master).Page 48 Too much of a good thing Too much of a good thing Too much of a good thing Each of the HART communication schemes usually work OK by itself. Primary Master talking to a field device Secondary Master talking to a field device Field device in Burst Mode communicating to a Tri-Loop Problems may arise if two or more of these schemes are applied together. HART traffic jamsoccur. Often the only way to remedy them is to live with a fewer number of simultaneous HART communication schemes.Page 49DemonstrationPage 50HART CommunicationsHART Communications--MultiplexersMultiplexersPage 51HART communication devices HART communication devicesHART communication devicesSeveral ways to communicate HART with a single FIELDVUE Instrument:Page 52HART Multiplexers HART MultiplexersHART MultiplexersWhat is a Multiplexer? A hardware means to have physical connectivity for HART communications to many field devices. Contains one or more HART modems that are shared sequentially among all connected field devices. Communicates with a host computer via RS485 (addressable serial data communication protocol) and communicates HART to all the connected field devices.Page 53What is a multiplexer ? What is a What is a multiplexermultiplexer??mul-ti-plex: being or relating to a system of transmitting several messages simultaneously on the same circuit of channelThink of it as a HART modem in a box with lots of simultaneous electrical connections.The four brands of HART multiplexers supported by AMS ValveLink Solo software: ARCOM (Rosemount 2530H1 HART Interchange) P & F KFD2-HMM-16 series ELCON 1700 and 2700 series MTL 4841 seriesPage 54RosemountType 2530H1 HART InterchangeRosemountRosemount Type 2530H1 Type 2530H1 HART InterchangeHART Interchange 32 channels per multiplexer Four independent HART modems One HART modem for every 8 channels(1 8, 9 16, 17 24, 25 32) Up to 32 multiplexers per RS485 serial network No backplane options requires an electrical tap into each monitored loop (a HART filter in the loop works good for this connection).Page 55Pepperl & FuchsKFD Series PepperlPepperl& Fuchs& Fuchs KFD SeriesKFD Series One master module, up to 15 slave modules, up to 256 channels per multiplexer Up to 31 multiplexers per RS485 serial network One HART modem shared among all 256 channels Various backplane optionsKFD0-HMS-1616 channel slave moduleKFD2-HMM-1616 channel master modulePage 56Pepperl & FuchsELCON HIS series PepperlPepperl& Fuchs& Fuchs ELCON HIS seriesELCON HIS series One master module with 32 channels Up to 32 multiplexers per RS485 serial network One HART modem shared among all channels Various backplane options, host FTA replacements Page 57MTL4840 series MTLMTL 4840 series4840 series One master module, up to 15 slave modules, up to 256 channels per multiplexer Up to 31 multiplexers per RS485 serial network One HART modem shared among all channels Various backplane options Page 58Typical Multiplexer Network Typical Multiplexer NetworkTypical Multiplexer Network(MTL4840 shown)MultiplexerMultiplexerField Termination AssemblyField Termination AssemblyRS485RS485Multi-address serialAddresses: 1 319600 38,200 baudOne HART modemsequentiallyserving 1 to manyfield devicesPage 59Network Alert Scan Network Alert ScanNetwork Alert Scan An application of AMS ValveLink Solo. Optimized to scan a defined population of FIELDVUE instruments as quickly as possible. It is the enginewithin AMS ValveLink Solo for Alert Scanning, Trending, and Modbus slave functionality. Freshness of HART information from the scanned population of FIELDVUE instruments is important.Page 60Network Alert Scan Network Alert ScanNetwork Alert ScanPage 61Mechanics of Network Alert Scan: Mechanics of Network Alert Scan:Mechanics of Network Alert Scan: HART Command 3 is issued to each FIELDVUE Instrument to gather its four primary variable values. If the More Status Availablebit is active in the HART Command 3 reply, ValveLink issues a HART Command 48 to gather the DVCs alert information.Page 62So how fast can the Network Alert Scan scan?So how fast can the Network Alert Scan So how fast can the Network Alert Scan scanscan??Refresh Time is the time it takes AMS ValveLink Solos Network Alert Scan to scan its entire population of FIELDVUE devices and update its Alert Log.Refresh Time = Multiplexer Refresh Time + Gathering TimeIt is a function of: ValveLink Network Alert Scan default settings Number of FIELDVUE Instruments in the scan list Number of FIELDVUE Instruments being served by one HART modem RS485 serial communication rates between ValveLink PCs COM port and multiplexers Any alert conditions existing in the FIELDVUE instrumentsPage 63Settings in Customize ValveLink Settings in Settings in Customize ValveLinkCustomize ValveLinkChanges from default settings:Set to maximumSet to minimumDe-select bothPage 64Multiplexer Refresh TimeMultiplexer Refresh Time Multiplexer Refresh Time 205 sec 256 Up to 256 1KFD SeriesP&F205 sec 256 Up to 256 14840 SeriesMTL7 sec 8 32 4 HARTInterchangeARCOM /Rosemount26 sec 32 32 1 1700/2700 ELCONRefresh Time (Max)Devices / Modem (Max)Channels Modems Model Manufacturer/Supplier Multiplexer Refresh Time is a function of the number of connected devices per multiplexer modem. This is calculated as 0.8 seconds per device per modem. Page 65Gather Time Gather TimeGather Time Gather Time is the rate AMS ValveLink Solo extracts instrument data from the multiplexers. This rate depends on the baud rate used by the PCs COM port to communicate over the RS-485 link to the multiplexers. 50 38.4K25 19.2 K15 9600Instruments per second Baud RatePage 66Gather Time Gather TimeGather TimeIf no alerts are present in the FIELDVUE instruments, the time required to gather data is calculated as:Gather Time (seconds) = (Number of Instruments / Instruments per sec) + 1If alerts are present in the FIELDVUE instruments, the time required to gather data is calculated as:Gather Time (seconds) = (Number of Instruments / Instruments per sec) + 1 + (Number of Instruments with active alerts)Page 67Example Refresh Time calculation -Two quad-modem ARCOM multiplexers:Example Refresh Time calculation Example Refresh Time calculation --Two quadTwo quad--modem ARCOM multiplexers:modem ARCOM multiplexers: 50 FIELDVUE instruments are connected to a multiplexer network consists of two ARCOM multiplexers. Each multiplexer has 25 instruments (7 on one modem, 6 on each of the other modems) connected to it. Three FIELDVUE instruments have alerts present. The multiplexer baud rate is 19.4K baud.Calculated Multiplexer Refresh Time:7 * 0.8 = 5.6 secondsCalculated Data Gathering Time:50/25 +1 + 3 = 6.0 secondsTotal AMS ValveLink Solo Refresh Time = 11.6 secondsPage 68What does this mean? What does this mean?What does this mean?Instead of second for one HART message:It will take 11.6 seconds for one HART message!The rest of the time, the HART modem isbusy talking to other FIELDVUE Instruments.Page 69Two single-modem multiplexers each with one slave module:Two singleTwo single--modem multiplexers each modem multiplexers each with one slave module:with one slave module: The same 50 FIELDVUE instruments are connected to a multiplexer network consists of two MTL or P&F multiplexers. Each multiplexer has a one slave module added to the master module with 25 instruments connected per mux. Three FIELDVUE instruments have alerts present. The multiplexer baud rate is 19.4K baud.Calculated Multiplexer Refresh Time:25 * 0.8 = 20.0 secondsCalculated Data Gathering Time:50/25 +1 + 3 = 6.0 secondsTotal AMS ValveLink Solo Refresh Time = 26.0 secondsPage 70 The same 50 FIELDVUE instruments are connected to a multiplexer network consists of one MTL or P&F multiplexer consisting of the master module and three slave modules. Three FIELDVUE instruments have alerts present. The multiplexer baud rate is 19.4K baud.Calculated Multiplexer Refresh Time:50 * 0.8 = 40.0 secondsCalculated Data Gathering Time:50/25 +1 + 3 = 6.0 secondsTotal AMS ValveLink Solo Refresh Time = 46.0 secondsOne single-modem multiplexer with three slave modules:One singleOne single--modem multiplexer modem multiplexer with three slave modules:with three slave modules:Page 71 The same 50 FIELDVUE instruments are connected to a multiplexer network consists of four MTL or P&F multiplexers consisting of only the master modules and no slave modules. The devices are unevenly distributed (16 + 16 + 16 + 2) Three FIELDVUE instruments have alerts present. The multiplexer baud rate is 19.4K baud.Calculated Multiplexer Refresh Time:16 * 0.8 = 12.8 secondsCalculated Data Gathering Time:50/25 +1 + 3 = 6.0 secondsTotal AMS ValveLink Solo Refresh Time = 18.8 secondsFour single-modem multiplexers with no slave modules:Four singleFour single--modem multiplexers modem multiplexers with no slave modules:with no slave modules:Page 72 The same 50 FIELDVUE instruments are connected to a multiplexer network consists of four MTL or P&F multiplexers consisting of only the master modules and no slave modules. The devices are more evenly distributed (13 + 13 + 12 + 12) Three FIELDVUE instruments have alerts present. The multiplexer baud rate is 19.4K baud.Calculated Multiplexer Refresh Time: 13 * 0.8 = 10.4 secondsCalculated Data Gathering Time:50/25 +1 + 3 = 6.0 secondsTotal AMS ValveLink Solo Refresh Time = 16.4 secondsFour single-modem multiplexers with no slave modules:Four singleFour single--modem multiplexers modem multiplexers with no slave modules:with no slave modules:Page 73Summary of Refresh Times with the various mux arrangements:Summary of Refresh Times with the Summary of Refresh Times with the various mux arrangements:various mux arrangements: Two quad-modem ARCOM multiplexers: 11.6 seconds Two single-modem multiplexers with one slave module each: 26.0 seconds One single-modem multiplexer with three slave modules: 46.0 seconds Four single-modem multiplexers with no slave modules (unbalanced load): 18.8 seconds Four single-modem multiplexers with no slave modules (evenly balanced load): 16.4 secondsData acquisition speed from a HART Multiplexer Network depends mainly upon the number of HART modems.Page 74What if the RS485 baud rate = 9600? What if the RS485 baud rate = 9600?What if the RS485 baud rate = 9600?Calculated Data Gathering Time:50/15 +1 + 3 = 7.3 seconds Two quad-modem ARCOM multiplexers: 11.6 seconds 12.9 seconds Two single-modem multiplexers with one slave module each: 26.0 seconds 27.3 seconds One single-modem multiplexer with three slave modules: 46.0 seconds 47.3 seconds Four single-modem multiplexers with no slave modules (unbalanced load): 18.8 seconds 20.1 seconds Four single-modem multiplexers with no slave modules (evenly balanced load): 16.4 seconds 17.7 secondsPage 75Multiplexer summary: Multiplexer summary:Multiplexer summary: Handy way to electrically connect numerous FIELDVUE Instruments to the PC software. Pay the price with HART scanning speed. The fastest scanning will be with the least number of devices per HART modem. Increasing RS485 baud rate helps, but not by much compared to HART modems. Load Balancing so that similar number of devices are on each modem optimizes the scanning speed.Page 76Data from a FIELDVUE Instrument via HARTData from a FIELDVUE Instrument Data from a FIELDVUE Instrument via HARTvia HART General device identification information HART tag, Manufacturer, Type, Serial number, etc. Parametric values 4 primary and several non-primary variables IEEE floating point format URV, LRV, and units code Device Status byte Available with every reply message Status Integrity bytes Available in response to a HART Command 48Page 77Network Alert Scan Network Alert ScanNetwork Alert Scan 16 DVC6000s 4 DVC6000s with active alerts Single modem multiplexer Communicating with ValveLink Solo at 38,400 baud Performing ValveLinks Network Alert Scan Refresh Time = = (16*0.8) + [(16/50) + 1 + 4]= (12.8) + (5.3) = 18.1 seconds Network Alert Scan gets update from every DVC6000 every 18 seconds.HART Modem#1#3#5#7#9#11#13#15#12#10#14#16#2#4#6#8Page 78What happens when a FIELDVUE Instrument experiences an intermittent fault?Is it detected by the Network Alert Scan?Page 79If a fault occurs and clears between messages?No indication!If a fault occurs during a HARTcommunication message? The active alert is indicated.HART sampling and communication of intermittent device faultsHART sampling and communication HART sampling and communication of intermittent device faultsof intermittent device faultsXXXXXX XXXIf a fault occurs when you are not communicating via HART?No indication!Hint:Enable the FIELDVUEs Alert Recordto capture these intermittent events. Page 80The DVCs Alert Record The DVCThe DVCs Alert Records Alert Record Like mailboxes, each record entry holds the alerts captured during one event. DVC5000 has 1 entry DVC6000 has 11 entries DVC2000 has 20 entries Events are captured at each cpu processing cycle. When at least one entry is populated, the Alert Record not Emptystatus is set. When all entries are populated, the Alert Record Fullstatus is set.Page 81Network Alert Scan can watch for the DVC Alert Record Network Alert Scan can watch for Network Alert Scan can watch for the DVC Alert Record the DVC Alert Record Scanning the device with Network Alert Scanwill pick up Alert Record Not Empty, even if thecaptured intermittent event failure has cleared.Page 82HART CommunicationsHART Communications--SummarySummaryPage 83What is HART communication? What is What is HARTHARTcommunication?communication? Superimposed 1200 baud digital communication signal on the Analog Control signal using the Bell 202 Frequency Shift Keying (FSK) standard. For a digital valve controller on an AO channel, the HART waveform is modulation of the loop voltage.TerminalVoltage2200 Hz1200 Hz"1" "0"+0.5 VDC- 0.5 VDCPage 84HART is: HART is:HART is: Question - Answerprotocol Primary / Secondary masters Burst Mode Communications Extremely politearbitration between mastersPrimary SecondaryPage 85What is a HART Filter ? What is a What is a HART FilterHART Filter??Acts like a wallto block HART signals from AO cards that would attenuate the HART waveform.Page 86What is a multiplexer? What is a multiplexer?What is a multiplexer?Think of it as a HART modem in a box with lots of simultaneous electrical connections. ARCOM (Rosemount 2530H1 HART Interchange) P & F KFD2-HMM-16 series ELCON 1700 and 2700 series MTL 4841 seriesHART Modem#1#3#5#7#9#11#13#15#12#10#14#16#2#4#6#8Page 87Typical Multiplexer Network Typical Multiplexer NetworkTypical Multiplexer NetworkMultiplexerMultiplexerField Termination AssemblyField Termination AssemblyRS485RS485Multi-address serialAddresses: 1 319600 38,200 baudOne HART modemsequentiallyserving 1 to manyfield devicesPage 88Troubleshooting tools: Troubleshooting tools:Troubleshooting tools:Network Alert ScanCommunication LogHART Audio MonitorPage 89Where to go for more information? Where to go for more information?Where to go for more information? DVC6000 Series FIELDVUEDigital Valve ControllerInstruction Manual, Form 5647 FIELDVUEHF300 Series HARTFiltersInstruction Manual, Form 5715 Audio Monitor for HARTCommunicationsInstruction Manual Supplement, Form 5811 HARTField Communication ProtocolInstruction Manual Supplement, Form 5812 Using the HARTTri-LoopHART-to-Analog Signal Converter with FIELDVUEDigital Valve ControllersInstruction Manual Supplement, Form 5813 FIELDVUE Product website: www.FIELDVUE.com HART Communication Foundation website: www.hartcomm2.org MTL Instruments website: www.mtl-inst.com Pepperl & Fuchs (P & F, ELCON) website: www.pepperl-fuchs.com ARCOM website: www.arcom.comPage 90Thank you for attending!! Thank you for attending!!Thank you for attending!!Questions?