ELEC-C1220 Automaatio 2 Prosessiautomaatio, luento 3 Panu Harmo
Sisällysluettelo: 1. Kenttälaiteintegraatio 2. Prosessiautomaation väylät 3. Integroidut automaatiojärjestelmät (DCS)
Prosessimittausten mittausviestit Standardoitu (4..20mA, 0-10V, Hart, kenttäväylät) Mittalaitteilta halutaan paljon muutakin tietoa kuin pelkkiä mittausarvoja: useampia eri antureita, kalibrointitietoja, diagnostiikkatietoa Mittalaitteita halutaan kalibroida ja kustomoida: yksi ja sama mittamuunnin, joka kustomoidaan toimimaan eri antureilla ja mittausalueilla Kenttäväylämittauksissa ollaan siirtymässä FDI standardin mukaisin mittalaitteisiin Field Device Integration (seuraavilla luennoilla lisää)
http://lamspeople.epfl.ch/kirrmann/slides/ai_411_hart.ppt Field device: example differential pressure transducer 4..20 ma current loop fluid The device transmits its value by means of a current loop
4-20 ma loop - the conventional, analog standard The 4-20 ma is the most common analog transmission standard in industry sensor flow transducer i(t) = f(v) reader 1 reader 2 voltage source 10V..24V R L1 R1 R2 R3 R L2 R L3 R L4 i(t) = 0, 4..20 ma R L4 conductor resistance The transducer limits the current to a value between 4 ma and 20 ma, proportional to the measured value, while 0 ma signals an error (wire break) The voltage drop along the cable and the number of readers induces no error. Simple devices are powered directly by the residual current (4mA), allowing to transmit signal and power through a single pair of wires. Remember: 4-20mA is basically a point-to-point communication (one source) http://lamspeople.epfl.ch/kirrmann/slides/ai_411_hart.ppt
3.3.2 HART Data over 4..20 ma loops 2005 April, HK http://lamspeople.epfl.ch/kirrmann/slides/ai_411_hart.ppt
http://lamspeople.epfl.ch/kirrmann/slides/ai_411_hart.ppt HART - Principle HART (Highway Addressable Remote Transducer) was developed by Fisher- Rosemount to retrofit 4-to-20mA current loop transducers with digital data communication. HART modulates the 4-20mA current with a low-level frequency-shift-keyed (FSK) sine-wave signal, without affecting the average analogue signal. Transmission of device characteristics is normally not real-time critical HART uses low frequencies (1200Hz and 2200 Hz) to deal with poor cabling, its rate is 1200 Bd - but sufficient. HART uses Bell 202 modem technology, ADSL technology was not available in 1989, at the time HART was designed
http://lamspeople.epfl.ch/kirrmann/slides/ai_411_hart.ppt HART - Protocol Hart communicates point-to-point, under the control of a master, e.g. a hand-held device Master Slave Request Indication time-out Response Confirmation Hart frame format (character-oriented): preamble start address command bytecount [status] data data checksum 5..20 (xff) 1 1..5 1 1 [2] (slave response) 0..25 (recommended) 1
http://lamspeople.epfl.ch/kirrmann/slides/ai_411_hart.ppt HART commands summary Universal Commands Read manufacturer and device type Read primary variable (PV) and units Read current output and percent of range Read up to four predefined dynamic variables Read or write eight-character tag, 16-character descriptor, date Read or write 32-character message Read device range values, units, and damping time constant Read or write final assembly number Write polling address Common Practice Commands Read selection of up to four dynamic variables Write damping time constant Write device range values Calibrate (set zero, set span) Set fixed output current Perform self-test Perform master reset Trim PV zero Write PV unit Trim DAC zero and gain Write transfer function (square root/linear) Write sensor serial number Read or write dynamic variable assignments Device-Specific Commands (example) Read or write low-flow cut-off Start, stop, or clear totalizer Read or write density calibration factor Choose PV (mass, flow, or density) Read or write materials or construction information Trim sensor calibration PID enable Write PID setpoint Valve characterization Valve setpoint Travel limits User units Local display information
HART - Importance Practically all 4..20mA devices come equipped with HART today About 40 Mio devices are sold per year. more info: http://www.hartcomm.org/ http://www.thehartbook.com/default.asp http://lamspeople.epfl.ch/kirrmann/slides/ai_411_hart.ppt
http://lamspeople.epfl.ch/kirrmann/slides/ai_411_hart.ppt Device Description Also known as Device Description Language (DDL) or eddl (electronic Device Description Language), electronic frontplate (Elektronisches Typenschild, plaque électronique))
Device access field device device volumetric flow rate type FlowPro manufacturer ABB volumetric flow rate cross sectional area: 3 cm2 pipe inside diameter 2 cm SCADA velocity 13.32 m2/s diff. pressure 9.8 Pa density 0.8 kg/l network adapter handheld device network adapter modem 4-20 ma loop for HART 13.32 9.8 0.8 transmission system (HART or field bus) http://lamspeople.epfl.ch/kirrmann/slides/ai_411_hart.ppt
http://lamspeople.epfl.ch/kirrmann/slides/ai_411_hart.ppt Device Description Language Device Description Language DDL allows a field device (slave) product developer to create a description of his instrument and all relevant characteristics, such that it can be represented in any host (master) device. The objective is common look-and-feel, independent of the hand-help or SCADA, similar to HTML for a web server.
EDDL Current field devices for process and factory automation have a number of configuration options, to customize them to their individual use case. For these means they are equipped with a digital communication interface (HART, PROFIBUS, Fieldbus Foundation). Different software tools provide the means to control and configure the devices. In the 1990s, the DDL was developed to remove the requirement to write a new software tool for each new device type. Software can, through the interpretation of a device description (DD), configure and control many different devices. The creation of a description with the DDL is less effort than writing an entire software tool. The HART Communication Foundation, PROFIBUS and Fieldbus Foundation have merged their individual dialects of the DDL. The result became the Electronic Device Description Language (EDDL), an IEC standard (IEC 61804).
Sisältö: Prosessiautomaation käytäntöjä ja standardeja: - Väylästandardit Kansainväliset IEC standardit Kenttälaitestandardit Tietojen välittäminen
Kenttälaitteiden integrointi automaatioon FDI Cooperation formed to support fieldbus device integration, InTech Magazne, 2012 http://www.isa.org/intechtemplate.cfm?template=/contentmanagement/contentdisplay.cfm&contentid=89183
Kenttälaitteiden integrointi automaatioon http://www.eddl.org/pages/default.aspx
Kenttälaitteiden integrointi automaatioon The Field Device Tool (FDT) interface is the specification describing the standardized data exchange between devices and control system or engineering or asset management tools for process/automation control systems. FDT standardizes the communication and configuration interface between all field devices and host systems. FDT provides a common environment for accessing the devices most sophisticated features. Any device can be configured, operated, and maintained through the standardized user interface regardless of supplier, type or communication protocol. http://www.fdtgroup.org/
Kenttälaitteiden integrointi automaatioon (erillinen esitys) Vertaa EDDL FDT (erillinen esitys) http://www.eddl.org/sitecollectiondocuments/about%20fdi/fdi%20technology%2003.pdf
Kenttälaitteiden integrointi automaatioon: prosessikenttäväylät Erillisiä esityksiä Profibus Foundation Fieldbus Hart
Integroidut automaatiojärjestelmät (DCS), esim. ABB 800xA AC 800M
Integroidut automaatiojärjestelmät (DCS) Prosessiautomaatiojärjestelmät Metso DNA (erillinen esitys) ABB 800xA Siemens PCS7 Honeywell Experion PKS Muitakin on. Nämä ovat meillä käytetyimmät. Näihin törmää joka paikassa