A Layman s s Guide to HART Communications with FIELDVUE Instruments

Transcription

1 A Layman s s Guide to HART Communications with FIELDVUE Instruments Jeff VonAhnen Rick Osborn FIELDVUE Technical Support Emerson Process Management Fisher Valve Division Marshalltown, Iowa

2 Presenters Jeff VonAhnen FIELDVUE Technical Support Rick Osborn FIELDVUE Technical Support Page 2

3 Digitally Communicating FIELDVUE Digital Valve Controllers Accurately control the valve Transmit device health Predict future valve performance Page 3

4 FIELDVUE Instruments Designed for Diagnostics Input current Supply pressure Port A pressure Actual Valve Travel Port B pressure Relay position Drive Signal Cycle Counter Travel Accumulator Triggered PD Profile 32 Device Alert and Status indicators I/P Drive Current Page 4

5 Alert Event Record (on-line) Network Alert Scan (alert events) (on-line) (alert log & trending) Vast Array of Diagnostics Available Performance Diagnostics (on-line) (graphs, interpretation) Dynamic Scan Diagnostics (off-line) (graphs, interpretation) Increasing Diagnostic Capability Page 5

6 But it all breaks down if you have HART Communications issues! DVC6000: HART Tag Device Disconnected RETRY QUIT F1 F2 F3 F4 DVC6000: HART Tag Access Restricted What causes such problems? What can be done? Instrument was taken Out of Service by another master. ABORT OK F1 F2 F3 F4 Page 6

7 Topics to be discussed: What is HART? Request Response HART 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 7

8 So, what is HART? Page 8

9 According to the HART 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 9

10 Overload! Overload! OK, let s slow it down a bit Page 10

11 HART Physical Layer - the electrical signals Page 11

12 First, what is Analog Control? Milliamp control signal created by an Analog Output channel. 4 to 20 milliamps represented 0% to 100%. Referenced relative to constant ground signal. Used to power coil of wire I/P valve instruments. Goal for Analog Output cards is to generate an accurate, smooth, steady, ripple-free signal Page 12

13 What is HART 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 13

14 What is HART 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 gorilla is for each kind of channel. Page 14

15 What is HART 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 ma Analog ma Signal ma 1200 Hz 2200 Hz "1" "0" Page 15

16 What is HART 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 VDC Terminal Voltage VDC 1200 Hz 2200 Hz "1" "0" Page 16

17 HART Communications - Possible Physical Layer problems Page 17

18 Electricity compared to water A handy way to think about voltage and current is 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). Pressure (voltage) volume (current) Page 18

19 FIELDVUE Compliance Voltage Required Compliance Voltage DVC5000 w/ HART: 12.0V w/o HART: 11.5V DVC6000 w/ HART: 11.0V w/o HART: 10.5V DVC2000 w/ HART: 9.0V w/o HART: 8.5V Measurable Terminal Voltage (typical) 11.0V 10.3V 8.3V The DVC takes the available system loop voltage and regulates it down to the Terminal Voltage values. Page 19

20 Insufficient Compliance Voltage can render the HART signal unreadable For a FIELDVUE instrument, the available loop compliance voltage needs to be at least 0.5 volts above what is needed for the DVC s terminal voltage. If the voltage droops below this level, the top half of the HART waveform will get clipped off and HART communication faults will occur V ± 0.15 V Available System Compliance Voltage 11.0 V minimum for DVC6000 System Compliance Voltage with HART communications 9.55 ± 0.15 V Measurable Terminal Voltage 4.0 ma 20.0 ma Page 20

21 This includes: Electrical noise can mess up the HART signals High strength Electro-Magnetic Interference (EMI) ( walkie talkie, arc welding, etc). Poor electrical wiring, shielding, and grounding practices. Page 21

22 The host DCS can mess up the HART signal Non-HART compatible AO channels may view the HART waveform as noise or AC ripple and may attenuate it down below size of a valid HART signal VDC Terminal Voltage VDC 2200 Hz 1200 Hz "1" "0" To keep the AO channel from reacting to the HART signal, a HF300-series HART Filter may be needed. Page 22

23 What is a HART Filter? Possibly misnamed does not do filtering as you would normally expect from an electrical filter circuit. Acts like a wall to block HART signals. HART signals existing on the field side of the HART filter cannot be seen on the system side. Page 23

24 Troubleshooting hint: 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 24

25 HART Communications - Master Communication Devices Page 25

26 HART is Question Answer A master HART device asks a question to the slave field device. The slave field device immediately answers this question. The slave device does not speak unless spoken to. Page 26

27 HART supports two masters talking to one 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. Primary Secondary Page 27

28 HART supports two masters talking to one slave device at the same time Rules 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 28

29 There is a third way Burst Mode A slave device can be configured to provide an answer without 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-Loop HART-to-Analog converter). Page 29

30 Burst Mode Communications Other masters ignore Burst Mode messages, 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 30

31 HART Command Arbitration The smooth interlacing of HART requests and slave replies to avoid collisions or 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) Burst Page 31

32 HART Communication Rate It takes about ½ second for one HART message: (single master shown) Page 32

33 HART Communications - HART Commands Page 33

34 Typical HART commands HART 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 34

35 Universal HART commands (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 Date Page 35

36 Common Use HART commands (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 Control Page 36

37 Device Specific Commands Not listed here - they are Proprietary. Allows for product uniqueness within an Open communication protocol. Used for special device functionality (diagnostics, etc.). Page 37

38 Format for various HART commands: Example HART Commands Master/Slave/Burst address command byte count status data checksum Command 3 M S D C1 B7 E C2 DC BD 7A E7 PV SV TV QV Command 33 M C D S C EB 1 st Slot 2 nd Slot 3 rd Slot 4 th Slot Variable Variable Variable Variable Command 48 m A4 s D4 Command 0 m s FE A Page 38

39 Device Status byte Available with every HART reply message: Bit 7 - Field Device Malfunction (hardware error or failure) Bit 6 - Configuration Changed Bit 5 - Cold Power-up (cleared by the 1st HART command) Bit 4 - More Status Available Bit 3 - Analog Input Fixed (set if DVC is OOS or in Digital Mode) Bit 2 - not used Bit 1 - Internal Sensor Out of Limits (travel, pressure, or temperature sensors reading beyond their limits) Bit 0 - Variable Out of Range (Primary Variable loop current out of -25% to +125% range) Page 39

40 HART 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) (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 40

41 Available user tool: ValveLink s Communication Log Right mouse click on HART tag for context menu Choose Communications Log Page 41

42 Running log of HART commands sent between ValveLink and DVC Newest... Oldest Full details of highlighted command Can be reviewed or exported and saved as a file. Page 42

43 HART Communications - Communication Errors Page 43

44 HART Communications errors DVC6000: HART Tag Device Disconnected RETRY QUIT F1 F2 F3 F4 DVC6000: HART Tag Access Restricted Instrument was taken Out of Service by another master. ABORT OK F1 F2 F3 F4 Page 44

45 What happens when things go wrong? You can get HART Communication Errors when: Two masters of the same gender talk at the same time on one loop. A host which doesn t arbitrate between multiple masters very well. Electrical noise messes up the HART signal. Unfortunately, it s hard to tell these apart! Page 45

46 Two masters of the same gender talking at the same time You 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 Manager or AMS ValveLink VL2000 Solo or the Moore Industries HIM can be either master, so they are the candidates to be moved out of the way. BUT there can only be ONE of any gender. Page 46

47 A host which doesn t t arbitrate between 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 47

48 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 jams occur. Often the only way to remedy them is to live with a fewer number of simultaneous HART communication schemes. Page 48

49 Demonstration Page 49

50 HART Communications - Multiplexers Page 50

51 HART communication devices Several ways to communicate HART with a single FIELDVUE Instrument: Page 51

52 HART Multiplexers What 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 52

53 What is a multiplexer? mul-ti-plex: being or relating to a system of transmitting several messages simultaneously on the same circuit of channel Think 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 series Page 53

54 Rosemount Type 2530H1 HART 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 54

55 Pepperl & Fuchs KFD Series KFD2-HMM channel master module KFD0-HMS channel slave module 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 options Page 55

56 Pepperl & Fuchs ELCON 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 56

57 MTL 4840 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 57

58 Typical Multiplexer Network (MTL 4840 shown) One HART modem sequentially serving 1 to many field devices RS485 Field Termination Assembly Multiplexer RS485 Multi-address serial Addresses: ,200 baud Field Termination Assembly Multiplexer Page 58

59 Network Alert Scan An application of AMS ValveLink Solo. Optimized to scan a defined population of FIELDVUE instruments as quickly as possible. It is the engine within 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 59

60 Network Alert Scan Page 60

61 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 Available bit is active in the HART Command 3 reply, ValveLink issues a HART Command 48 to gather the DVC s alert information. Page 61

62 So how fast can the Network Alert Scan scan? Refresh Time is the time it takes AMS ValveLink Solo s Network Alert Scan to scan its entire population of FIELDVUE devices and update its Alert Log. Refresh Time = Multiplexer Refresh Time + Gathering Time It 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 PC s COM port and multiplexers Any alert conditions existing in the FIELDVUE instruments Page 62

63 Settings in Customize ValveLink Changes from default settings: De-select both Set to maximum Set to minimum Page 63

64 Multiplexer Refresh Time 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. Manufacturer/ Supplier Model Modems Channels Devices / Modem (Max) Refresh Time (Max) ELCON 1700/ sec ARCOM / Rosemount HART Interchange sec MTL 4840 Series 1 Up to sec P&F KFD Series 1 Up to sec Page 64

65 Gather 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 PC s COM port to communicate over the RS-485 link to the multiplexers. Baud Rate Instruments per second K 38.4K Page 65

66 Gather Time If 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) + 1 If 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) (Number of Instruments with active alerts) Page 66

67 Example Refresh Time calculation - Two quad-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 seconds Calculated Data Gathering Time: 50/ = 6.0 seconds Total AMS ValveLink Solo Refresh Time = 11.6 seconds Page 67

68 What does this mean? Instead of ½ second for one HART message: It will take 11.6 seconds for one HART message! The rest of the time, the HART modem is busy talking to other FIELDVUE Instruments. Page 68

69 Two single-modem multiplexers each 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 seconds Calculated Data Gathering Time: 50/ = 6.0 seconds Total AMS ValveLink Solo Refresh Time = 26.0 seconds Page 69

70 One single-modem multiplexer with three slave modules: 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 seconds Calculated Data Gathering Time: 50/ = 6.0 seconds Total AMS ValveLink Solo Refresh Time = 46.0 seconds Page 70

71 Four single-modem multiplexers with no slave modules: 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 ( ) Three FIELDVUE instruments have alerts present. The multiplexer baud rate is 19.4K baud. Calculated Multiplexer Refresh Time: 16 * 0.8 = 12.8 seconds Calculated Data Gathering Time: 50/ = 6.0 seconds Total AMS ValveLink Solo Refresh Time = 18.8 seconds Page 71

72 Four single-modem multiplexers with no slave modules: 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 ( ) Three FIELDVUE instruments have alerts present. The multiplexer baud rate is 19.4K baud. Calculated Multiplexer Refresh Time: 13 * 0.8 = 10.4 seconds Calculated Data Gathering Time: 50/ = 6.0 seconds Total AMS ValveLink Solo Refresh Time = 16.4 seconds Page 72

73 Summary of Refresh Times with the 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 seconds Data acquisition speed from a HART Multiplexer Network depends mainly upon the number of HART modems. Page 73

74 What if the RS485 baud rate = 9600? Calculated Data Gathering Time: 50/ = 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 seconds Page 74

75 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 75

76 Data from a FIELDVUE Instrument via 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 48 Page 76

77 Network Alert Scan 16 DVC6000s #1 4 DVC6000s with active alerts #3 #2 Single modem multiplexer #5 #4 Communicating with ValveLink Solo at 38,400 baud HART Modem #7 #9 #6 #8 Performing ValveLink s Network Alert Scan Refresh Time = #11 #10 = (16*0.8) + [(16/50) ] #13 #12 = (12.8) + (5.3) = 18.1 seconds #15 #14 #16 Network Alert Scan gets update from every DVC6000 every 18 seconds. Page 77

78 What happens when a FIELDVUE Instrument experiences an intermittent fault? Is it detected by the Network Alert Scan? Page 78

79 HART sampling and communication of intermittent device faults If a fault occurs when you are not communicating via HART? No indication! XXX XXX XXX If a fault occurs during a HART communication message? The active alert is indicated. If a fault occurs and clears between messages? No indication! Hint: Enable the FIELDVUE s Alert Record to capture these intermittent events. Page 79

80 The DVC s s 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 Empty status is set. When all entries are populated, the Alert Record Full status is set. Page 80

81 Network Alert Scan can watch for the DVC Alert Record Scanning the device with Network Alert Scan will pick up Alert Record Not Empty, even if the captured intermittent event failure has cleared. Page 81

82 HART Communications - Summary Page 82

83 What is HART 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 VDC Terminal Voltage VDC 1200 Hz 2200 Hz "1" "0" Page 83

84 HART is: Question - Answer protocol Primary Secondary Primary / Secondary masters Burst Mode Communications Extremely polite arbitration between masters Page 84

85 What is a HART Filter? Acts like a wall to block HART signals from AO cards that would attenuate the HART waveform. Page 85

86 What is a multiplexer? #1 #3 #5 #2 #4 Think of it as a HART modem in a box with lots of simultaneous electrical connections. #7 #6 HART Modem #9 #8 ARCOM (Rosemount 2530H1 HART Interchange) #11 #10 P & F KFD2-HMM-16 series #13 #15 #12 #14 ELCON 1700 and 2700 series MTL 4841 series #16 Page 86

87 Typical Multiplexer Network One HART modem sequentially serving 1 to many field devices RS485 Field Termination Assembly Multiplexer RS485 Multi-address serial Addresses: ,200 baud Field Termination Assembly Multiplexer Page 87

88 Troubleshooting tools: Network Alert Scan Communication Log HART Audio Monitor Page 88

89 Where to go for more information? DVC6000 Series FIELDVUE Digital Valve Controller Instruction Manual, Form 5647 FIELDVUE HF300 Series HART Filters Instruction Manual, Form 5715 Audio Monitor for HART Communications Instruction Manual Supplement, Form 5811 HART Field Communication Protocol Instruction Manual Supplement, Form 5812 Using the HART Tri-Loop HART-to-Analog Signal Converter with FIELDVUE Digital Valve Controllers Instruction Manual Supplement, Form 5813 FIELDVUE Product website: HART Communication Foundation website: MTL Instruments website: Pepperl & Fuchs (P & F, ELCON) website: ARCOM website: Page 89

90 Thank you for attending!! Questions? Page 90