calibrating and trimming instruments via hart
TRANSCRIPT
-
8/13/2019 Calibrating and Trimming Instruments via HART
1/13
Calibrating and Trimming Instruments via HARTAgenda:
What is HART? / History / Signal / Message Frame HART Command Structure
Connecting a HART Transmitter Trimming Devices Trimming Conventional Transmitter vs. HART Transmitter Live Demo
-
8/13/2019 Calibrating and Trimming Instruments via HART
2/13
What is HART?HART = Highway Addressable Remote Transducer
A digital communication protocol designed for industrial processmeasurement applications.
Uses a low-level modulation (FSK) superimposed on the standard4 to 20 mA current
-
8/13/2019 Calibrating and Trimming Instruments via HART
3/13
HART HistoryRevision Year
2.0 19873.0 19884.0 19895.x 1989 still
delivered today6.0 2001
never introduced7.0 2007
introduction of HART wireless
-
8/13/2019 Calibrating and Trimming Instruments via HART
4/13
HART Signal
-
8/13/2019 Calibrating and Trimming Instruments via HART
5/13
HART Message Frame
-
8/13/2019 Calibrating and Trimming Instruments via HART
6/13
HART Command StructureThree levels of commands Universal commands Common practise commands Device Specific commands
Universal commandsModel IDTag IDDescriptionMessageDateRange ValuesInstrument LimitsProcess MeasurementsDevice Status
Common practice commandsRead VariablesCalibration (zero, span)Initiate Self TestsSerial NumberTime Constant Values
Device Specific commandsModel Specific FunctionsStart, Stop, or Clear TotalizerSelect Primary VariableSpecial Calibration OptionsPID - SP, Tuning, Etc.
-
8/13/2019 Calibrating and Trimming Instruments via HART
7/13
Connecting a HART TransmitterPoint-to-point
24V supply
+
_
ResistorTransmitter
HARTCommunicator
mA
mA
Polling address = 0 !=> HART + mA signal
HART
-
8/13/2019 Calibrating and Trimming Instruments via HART
8/13
Connecting a HART transmitterMultidrop
24V supply
+
_
Resistor
Transmitters (max 15 pcs), fixed 4 mA current,Only PV output, different addresses (not 0 !)
HARTCommunicator
4 mA(fixed)
...
Addr=1 2 15
-
8/13/2019 Calibrating and Trimming Instruments via HART
9/13
Trimming Devices
Communicators Smart Calibrators
-
8/13/2019 Calibrating and Trimming Instruments via HART
10/13
MC5 Internal Connections
24V supply
+
_
ResistorTransmitter
HARTCommunicator
mA
mA
MC5
+24V
Ground
HART
-
8/13/2019 Calibrating and Trimming Instruments via HART
11/13
HART vs. Conventional Transmitter (1of 2)
Conventional transmitter
Input 4 20 mA
Adjustments: Zero Span
-
8/13/2019 Calibrating and Trimming Instruments via HART
12/13
HART vs. Conventional Transmitter (2 of 2)
HART transmitter
Input 4 .. 20 mA
Digital trim Analog trim
RangeTransferFunction
PV
PV
Input section Output sectionConversion
AO
AO
A/D D/A
-
8/13/2019 Calibrating and Trimming Instruments via HART
13/13
Live Demo
Presented by:Ned Espy Consulting Director
Beamex, Inc.Office: 770-951-1927Mobile: [email protected] www.beamex.com
mailto:[email protected]://www.beamex.com/http://www.beamex.com/mailto:[email protected]