我们新研制出一种用于纸浆白度测定的智能白度仪，该仪表采用西门子公司生产的S7-224 CPU结合软件功能进行数据处理，具有较好的可靠性、重复性、精确度和稳定性。为了使其能与其它智能设备之间实现通信，我们将通过现场总线技术把它连接到网络中，使它成为造纸厂现场总线控制系统的一部分。

2.现场总线的选择

  2.1现场总线技术的选择

  现场总线集控制技术、计算机技术、通信技术于一体，是当今自动化领域技术发展的热点之一。这项技术可将多个智能控制仪表连接成网络系统，实现分布式计算机控制，提高检测和控制精度，改善系统的动态响应速度，提高系统安全性，从而得到了广泛的应用。

  近年来，几种有影响的现场总线技术已在一些特定的应用领域里显示出各自的优势。在此，我们选定了现为德国和欧洲标准的PROFIBUS（Process Fieldbus）现场总线。一方面由于它是目前数据传输率快的一种现场总线，传输率高可达12Mbps，另一方面它能够很好的与西门子的传动设备相配合，并与西门子PLC（Programmable Logic Controller）结合紧密且组态简便。

  2.2 PROFIBUS现场总线简介

  参照ISO/OSI参考模型,PROFIBUS现场总线只包含物理层、数据链路层和应用层。由PROFIBUS-DP，PROFIBUS-FMS， PROFIBUS-PA组成PROFIBUS系列。

  PROFIBUS-DP：经过优化的高速、廉价的通信连接，专为自动控制系统和设备级分散I/O之间通信设计，使用PROFIBUS-DP模块可取代价格昂贵的24V或0～20mA并行信号线。用于分布式控制系统的高速数据传输。

  PROFIBUS-FMS ：解决车间级通用性通信任务，提供大量的通信服务，完成中等传输速度的循环和非循环通信任务，用于纺织工业、楼宇自动化、电气传动、传感器和执行器、可编程序控制器、低压开关设备等一般自动化控制。

  PROFIBUS-PA专为过程自动化设计，标准的本质安全的传输技术，实现了IEC1158-2中规定的通信规程，用于对安全性要求高的场合及由总线供电的站点。

  本设计中采用的是PROFIBUS-DP标准，PROFIBUS-DP（或DP标准）是由欧洲标准EN50170定义的一种远程I/O通信协议。DP表示分布式外围设备，亦即远程I/O。PROFIBUS-DP还用到了应用层接口（ALI），ALI将过程对象转换为通信对象。

3M-Matic 700r Random Case Sealer, 15 boxes per min!
83420A K23 Amp Pair Source Test Set
83420A K25 Branching Unit Source #1 Test Set
83420A K26 Branching Unit Receiver Test Set
83420A K29 Branching Source #2 Test Set
Adtech 400120C VXI Mainframe (Reduced!)
Adtech SX/14 Data Link Simulator Mainframe (Reduced!)
Advanced Energy MDX Magnetron Drive 2172
Agilent 35670A opts AY2/1D0/1D1/1D2?/1D3/1D4/1C2
Agilent 53310A Modulation Domain Analyzer w/ opt's 
Agilent 70420A Phase Noise Test Set w/ opt 001
Agilent 8509B Lightwave Polarization Analyzer
Agilent E1437A VXI Digitizer Module 
Agilent E1439A VXI Digitizer Mod. (Reduced!)
Agilent E1441A opt 001 Arbitrary Waveform Generator
Agilent N1610B Service Advisor Portable Test Tablet 
Agilent N4483A 
Alloyd 2SC1016 Dual Shuttle Sealer, 10 x 16!
Alzmetall AB3R Drilling Machine
Amtech Ultraweld 20 Precision Ultrasonic Welder
Anritsu MD1620B Signaling Tester w/ opt 01 / 11
Anritsu MG3670B Modulation Signal Generator w/ opt's
Anritsu MG3670B Modulation Signal Generator w/ opt's
Applied Systems Eng.167KU 300 Watt TWT (Reduced!)
Aremco 2928-B Heat Furnace 2 (Reduced!)
Azco FG160 SUR-PAK Precision Cutting Machine
Barnstead / Labline 3628A-1 Lab Oven
Barnstead Fistreem II / A74415-60 Distiller (Reduced!)
Beckman L5B-CT Ultracentrifuge with Rotor (Reduced)
Biddle 247000-7 Digital Low Resistance Ohmmeter
Biddle 247000-8 Digital Low Resistance Ohmmeter
Biddle 247800 Digital Microhmmeter
Bio Rad UMA-500 Spectroscopic Microscope, 15x & 4x
Bio-Rad FTS 45 FT-IR Spectrometer w/UMA 300A FTIR
Blue M 1004-8C-MP3 Environmental Test Chamber
Blue M DC-206C Convection Oven
Blue M IGF-7780F Environmental Oven 1100°F
Blue M Lindberg WSP-109C-MP3 Shock Chamber (Reduced!)
Blue M POM7-206C-2X Convection Oven
Blue M WSP-109B-3 Shock Chamber Oven
Boonton 4300 RF Power Meter
Bruel & Kjaer 4602B w/ 4185 & Accessories (Reduced)
Budzar BTU Multi-Zone Electrically HeatedTemp. Unit
Caliper Life Science Tekmar Autotrace SPE Workstation
Carver 3947Auto Pak (Reduced!)
Chase Machine & Engineering Oven Module
Cheminstruments AR-1500 Adhesion Release Tester
Clausing Colchester 11 Lathe w/ Accessories
Clinton STB-10G DC Spark Tester 
Coherent Innova 90-6 with LaserPure 20N & Power Supply
Complete Kit
Coulter Delsa 440 Particle Counter w/ Power Supply
Cumberland 284 Pelletizer, Granulator
CyberOptics MicroScan Laser Measure System
CyberOptics MicroScan Laser Measure Unit
Danly 5 Ton, Four Post Air Press (Reduced!)
Datatape TMA3000 Tape Motion Analyzer
Delta Design 9059 Environmental Test Chamber, 2-3-1
Despatch LBB2-12-1 Forced Convection Oven
Despatch LFD2-24-3 Forced Air Oven
Despatch LND1-42-2 600°F Inert Atmosphere Oven
DLS Test Works DLS400 ADSL Wireline Simulator
DRANETZ PP1-P 
DRANETZ PP1-R 
Dukane 410 Series Ultrasonic Wedling System
Dukane 410 Series Ultrasonic Wedling System
Dukane Lot of Qty 2 43A240 & Qty 1 Ultra 351 Auto-Trac
DynaMyte 4000 Milling Machine 
Each Brand New Cell Phone is Complete with Accessories
Edwards High Vacuum Pump (Reduced)
Electroglas EG5 / 300 ARGOS Wafer Prober (Reduced!)
EMCO 5101 Dual TEM Cell (Reduced!)
EMI TCR100T50 DC Power Supply (Reduced)
Empire Pro-Finish FS-2636 3 Piece System!
ENI ACG-3 RF Power Generator
ENI EGR9600B Power Generator 9,000 Watts (Reduced)
ENI POWER SYSTEMS OEM-25 RF Generator
ESI 231C 
ETS Lindgren T/T RF Enclosure w/ Anechoic Absorber
EXFO FTB-300 w/opt's D2/M1/W1/N4 (Reduced!)
Extek 3100 Silver Film Duplicator w/ Manual/Accessor?ies
Fargo HDP720 High-Definition Card Printer
Fisher Scientific Isotemp Plus Freezer 13-986-146RA
Forma Scientific 3908 Reach-In Incubator
GCI DE1AC Air Conensing Chiller
Giga-tronics 6082A opt 130 Synth Sig Gen (Reduced!)
GL Communication Inc. 9121TB1G8CE
GLSI Hg253 Portable Vapor Mercury Analyzer
Gorman Bobbineer Wire Winding Machine
Graco Air Powered Pump with Drum
Graphtec DMS1000 Data Management System
GSI ScanArray 3000 Microarray Scanner
Hankison HPRP0.75CU Compressed Air Dryer 
Hardinge DV-59 / DSM-59 Industrial Lathe
Heller 1148 IRC Reflow Convection Oven
HP / Agilent 81110A (Reduced!)
HP / Agilent 81685A Amplifier Test Set (Reduced!)
HP 11729C Carrier Noise Test Set, 10MHz to 18GHz
HP 16190A Performance Test Kit, Complete
HP 16453A Dielectric Material Test Fixture
HP 16454A Magnetic Material Test Fixture, Complete
HP 3326A 2-Channel Synthesizer w/ opt's 002 & 003
HP 35660A-001 Dynamic Signal Analyzer (Reduced!)
HP 35665A
HP 35665A opts 1C1/1C2/1D0/1D2?/ANA
HP 3585A Spectrum Analyzer, 20 Hz - 40 MHz (Reduced!)
HP 4352B VCO / PLL Signal Analyzer (Reduced!)
HP 4380A 500 MHz S-Parameter Test Set (Reduced!)
HP 5183T Precision Digitizing Oscilloscope
HP 5350B Microwave Frequency Counter
HP 54007A Infinium Accy kit (Reduced!)
HP 54620C Logic Analyzer
HP 54825A Infinium Oscilloscope, 500MHz, 2GSa/s
HP 6674A opt J06 (70V -30A) DC Power Supply (Reduced!)
HP 70621A 2.9 GHz Preamplifier Module (Reduced!)
HP 70841B PatternGenerato?r 100 Mb/s to 3Gb/s (Reduced!)
HP 70842B Error Detector Module (Reduced!)
HP 70842B Error Detector Module w/ Opt H50 (Reduced!)
HP 8146A opt 003 (Reduced)
HP 83420A opts 014 / 210 (Reduced!)
HP 85027C Directional Bridge 10 MHz to 18 GHz
HP 8510C opt 010 50 GHz Network Analyzer (Reduced!)
HP 8514B S-Parameter Test Set
HP 8515A S-Parameter Test Set
HP 8590D Opt. 001 Spectrum Analyzer 1.8GHz (Reduced)
HP 8590D Opt. 003 Spectrum Analyzer 1.8 GHz (Reduced)
HP 8643A Signal Generator Opt. H02
HP 8757A Scalar Network Analyzer (Reduced!)
HP 89441A Vector Signal Analyzer AYA / AYB / AY9 / UFG
HP 8981A Vector Modulation Analyzer (Reduced!)
HP 8981B Vector Modulation Analyzer
HP A2638B Industrial Computer Workstation 9000
HP Agilent 3563A Control Systems Analyzer, 100 kHz
HP Agilent 35670A Dynamic Signal Analyzer w/ opt's
HP Agilent 35689B S-Parameter Test Set, 150 MHz
HP Agilent 3709B Constellation Analyzer 
HP Agilent 4193A Vector Impedance Meter, 110MHz
HP Agilent 4274A LCR Meter w/ opt 001
HP Agilent 5183U Precision Digitizing Oscilloscope
HP Agilent 53310A Communication Analyzer
HP Agilent 5361A CW Microwave Counter, 10Hz to 20 GHz
HP Agilent 5373A Domain Pulse Analyzer (Reduced!)
HP Agilent 6674A-J05 Programmable Power Supply
HP Agilent 83540B Sweep Generator, 2-8.4 GHz (Reduced!)
HP Agilent 83592C Sweeper Plug-In (Reduced!)
HP Agilent 83621A Synthesized Signal Generator
HP Agilent 8510B Network Analyzer Set, with Cable!
HP Agilent 8590A Spectrum Analyzaer, 10kHz to 1.5GHz
HP Agilent 8590B 1.8 GHz Spectrum Analyzer w/ opt 021
HP Agilent 8591E Portable Spectrum Analyzer w/ opt 105
HP Agilent 8665A Signal Generator 100KHz - 4.2GHz
HP Agilent 8760A K72 Performance Test Matrix (Reduced)
HP Agilent 8922M GSM Mobile Station Test Set w/ Opt's
HP Agilent 8991A Peak Power Analyzer w/ opt 003
HP Agilent E1413C High-Speed 64-Channel Converter
HP Agilent E4431B Digital RF Signal Generator (Reduced)
HP Agilent WireScope 350 Cable Certifier (Reduced!)
HP C6075A DesignJet 1055CM 36 Plotter
HP E1431A VXI Digitizer Module 8-Ch
HP E4433B opt's 1E5/UND/UN4/UN5?/UN7
HP/Agilent 5508A Laser Measurement Display
HP/Agilent 70909A 26.5 GHzRF Section Module (Reduced!)
HP/Agilent 85046A S-Parameter Test Set (Reduced!)
HP/Agilent 85062A 3.5-mm E-Cal Module w/ opt's 001/00F
HP/Agilent 8566A Spectrum Analyzer System (Reduced!)
HP/Agilent 89410A opt's AYA,AYB,AY9,UFG (Reduced!)
HP/Agilent 89411A Network Analyzer Downconverter
HP/Agilent 89431A Vector Signal Analyzer
HP/Agilent E9850A VXI Embedded PC Controller
Ideal 3915-95 Guilotine, New, with Accessories
Includes Manual, Software & Ammonia Cabinet
Instrument Systems RPA2000 (Reduced!)
Integrated Air Systems LV4-30 Laminar Flow Hood
IRD 350 Vibration Analyzer (Reduced!)
Ithaco 1201 Low Noise Preamplifier
Jouan CR 412 Refrigerated Centrifuge
K&E Vectron Transit Theodolite
Kaye Instruments HTR150 Temperature Reference(Reduc?ed!)
Keithley 237 High Voltage Source-Measure Unit (Reduced)
Kester KWB-1000 Automated Wetting Balance Tester
Knight Tool Co. KTC-FT-54 Press 
Knight Tool Co. KTC-FT-62 Press 
Koolant Koolers KV2000 Industrial Chiller
Koolant Koolers, Inc. KV1500 Chiller (Reduced!)
Labline 4628 Obrital Shaker
Lambda EMI ESS 500-6 DC Power Supply
Laser Precision Corp Optical Time Domain Reflectometer
LeCroy 9304AM Digital Oscilloscope w/ Options
LeCroy 9350AM Digital Oscilloscope w/ Options
LeCroy DDA-120 1.0 GHz, 4 Channel 8GS/sec Oscilloscope
LeCroy LC574A Digital Oscilloscope w/ Options
Leica Wild 355110 Dual Head Microscope
Lindgren ETS Series 81 RF Shielded Room 9' x 7' x 8'
LMI SE2050 Laser Engraver (Reduced!)
LMT Model LD-390 Component Lead Trim
Lot of 10 Katadyn Survivor 35 Reverse Osmosis, New
Lydall Affinity CBD-007S-BB09C-?BD3 Chiller
Lydall Affinity RAA-002H-BB06C-?BD3 Chiller
Lydall Affinity RAA-002H-BB06C-?CBC3 Chiller
Lydall Affinity RAA-002H-BB06C-?CBS Chiller
Maag Flockmaschinen SPG 1000 Rise Time Tester
Mahr Federal 832F Digital Electronic Amplifier
Marconi 2022D Signal Generator, 10kHz-1GHz.
Marconi 2305
Mattson Polaris IR-10410 FTIR Spectrometer (Reduced!)
Mech-El Industries 709 Manual Eutectic Die Attacher
MetOne A2408-1-115-1 Portable Laser Particle Counter
Metrum MET64SCUA 8000 Speed (Reduced!)
Metrum MET64SCUAO 4000 Speed (Reduced!)
Metrum VLDSB Data tape Recorder (Reduced!)
Micro Robotics Systems Inc Model 170G (Reduced!)
Microautomation M-150 Mounting Station 
Micro-Quad 8000 Infrared Analyzer w/ 2 Sensors
Microtrac FRA 9250 Particle Size Analyzer
Millipore Waters Quanta 4000E (Reduced)
Miteq DN-8011 Satellite Test Loop Translater
Mitsubishi CA-06 Moisture Meter
Mitutoyo PH-350A Optical Comparator
Mobicom Accetio 2189 Lot of 1000, All New (Reduced)
Molecular Devices Cytosensor Microphysiomete?r 
MPM SP-1500 Semi-Automatic Screen Printer
Mystaire 2450 Ductless Fume Enclosure
Narda 8011B RF Transparent Temperature Monitor
NBSC InnOva 2100 Platform Shaker w/ User Manual
NHI NHI-2040MW-10L Solid State Amplifier
Nicolet Model 730 FTIR Spectrometer with AEM Module
Nikon Linear Measurescope 20 LS-403 Stage
Nikon Measurescope 20 LS-402 Stage
Nikon SMZ800 Stereomicroscop?e w/ SDC-240 Digital Camera
Noise/Com Model UFX-BER 892/1850 Precision CN Generator
NoiseCom 7107 Noise Generator (Reduced!)
NoiseCom UFX 7907 Prog. Noise Generator (Reduced!)
Noisecom UFX-BER 892 / 1850 Precision C/N Generator
Noisecom UFX-BER-30/65/1?45 (Reduced!)
NoiseCom UFX-BER-375/625 C/N Generator (Reduced!)
OCE G6035-S Scanner
Olympus SZ6045 Stereo Imaging Microscope System
Ono Sokki CL-250 Non-Contact Thickness Meter (Reduced!)
Optical Associates INC 316 UV Power Meter with Probe
Orec Model 03DM-100 Ozone Monitor
Perkin Elmer ABI Prism 7700 Sequence Detector
Perkin Elmer Arnel Autosampler
Perkin Elmer Autosystem Gas Chromatograph
Perkin Elmer LC-100 Column Oven
Perkin Elmer Series 410 Liquid Chromatograph Pump
Perkin Elmer Sigma 10 Chromatography Data Station
Precision Scientific Model 29 Vacuum Oven
Quadtech 1870 AC DC Dielectric Analyzer
Quadtech 1880 (Reduced!)
QuadTech Guardian 12kV DC Hipot Tester w/ Accessories
Rapid-Air R34F Stock Reel
Rheometrics RSA 2 Solids Dynamic Mechanical Analyzer
Rohde & Schwarz CMD55 Com Test Set w/ opt's and manuals
Rohde & Schwarz FSEB20 Spectrum Analyzer 
Rohde & Schwarz UPL16 Audio Analyzer (Reduced)
Rohde & Schwarz UPL16 w/ Options & Accessories
Ruska DDR 6000
Sahara S1 FC5 Drum Heater Oven
Schaffner NSG 431 Electrostatic Discharge System
Sencore SC3100 Oscilloscope (Reduced!)
SES TK/20S Temperature Chamber
Seven Associates B-1A Induction Heating Unit
Solartron 1254 Frequency Response Analyzer (Reduced!)
Solartron/Schlu?mberger 1253 Gain Phase Analyzer.
Solitec Edwards High Vacuum Pump System
Sony VPH-1292Q Multiscan Projector (Reduced)
Sony VPH-G70 CRT Projector (Reduced)
Sorensen DHP50-60 DC Digital Power Supply
Spencer Industravac SA607A Air Clean System (Reduced!) 
Spirent Abacus1 Call Simulator System w/opt's (Reduced)
Spirent TAS 4500C RF Channel Emulator
SSEC Evergreen M10 Wafer & Mask Cleaner 
Standard Environmental Systems Temperature Chamber
Stanford Research SR645 
Sunol Sciences Corporation SC98V
Systron Donner 6530 Microwave Frequency Counter
TA Instruments TMA2940 Thermomechanica?l Analyzer
TDI RBL-488-400-120?-800 DC Electronic Load
Tektronix 1740 Waveform / Vector Monitor (Reduced!)
Tektronix A6909 Two Channel Isolator 
Tektronix AGL1 Analog Generator Lock Option Module
Tektronix AVG1 Multiformat Analog Test Signal Generator
Tektronix CTS 710 Sonet Test Set w/Opt 003 (Reduced!)
Tektronix CTS 710 w/ Opts 004 / 022 (Reduced!)
Tektronix DL-11 Delay Line (Reduced!)
Tektronix DTG5274 Data Time Generator w/ Modules
Tektronix GB1400 Analyzer/Genera?tor Test Set (Reduced)
Tektronix GB1400 GigaBert Analyzer w/ Opt's 08 & 09
Tektronix PB200 Packet / Cell BERT Tester (Reduced!)
Tektronix PQA300 Picture Quality Analysis System 
Tektronix TDS520B 500 MHz Oscilloscope (Reduced!)
Tektronix TDS540 Digitizing Oscilloscope
Tektronix TLA7L3 Logic Analyzer Module w/ opt's 1S & 2S
Tektronix VM700 Video Test Set w/ opt's 01 (Reduced!)
Tektronix VM700A Automatic Video Measurement Set w/ opt
Tektronix VM700A opt;s 01 / 30 / 40 (Reduced!)
Tektronix VM700A opt's 01/ 40 (Reduced!)
Tektronix VX4101A w/opt's 1A/1D (Reduced!)
Teledyne Taber V-5 150-B Electric Stiffness Tester
Telsonic USP3000 Ultrasonic Welding System
Tenney / Lunaire T-Series Environmental Chamber
Tensile Testers, Inc JDH Tensile Strength Tester
Thermotron S-32C Environmental Chamber
Toddco General Inc CH200 (Reduced!)
Transistor Devices DLVP130-250-250?0 DC Electronic Load
TTC / Acterna T-Berd 224 PCM Analyzer (Reduced!)
TTC 43440 DS1 / DS3 ATM Interface Adapter, New in Box!
Ultratech 602 Wafer & Mask Cleaner
Unadyn UDC-55 Mini Dryer with 300 Modular Hopper
Union Special 35800 DR Felling Machine
Uson Testra 1100 Gauge Decay Tester
Valhalla 2301 Power Analyzer, 2 Available!
Vestil 4853 / Scale Hydrolic Scissor Lift
Vestil EHLTX-4855-1-39 Hydrolic Scissor Lift
Vickers Hydraulic Power Unit, 10 Gal Per Minute
Vickers Hydraulic Power Unit, 5 Gal Per Minute
Vision Engineering Cobra Stereo Zoom Microscope
Vision Engineering Model TS-3 Dynascope
Wandel & Goltermann OSA-155 DWDM System Analyzer
Wandel & Goltermann RME-5 / RMS-5 System (Reduced!)
Wandel & Goltermann RS-100 White Noise Generator
Watson KRPS2-CB-1 Single Position Payoff 
Watson PS2-CB-1 Single Position Payoff 
Watson PS2-CB-2 Dual Position Payoff 
WaveTek 1395 Arbitrary Waveform Synthesizer
Wavetek 195 Waveform Generator w/opt 01, 02 (Reduced!)
Wavetek 4600 Autocal Amp (Reduced !)
Wavetek 4808 Multifunction Calibrator
Wayne Kerr PSG 2400L Sweep Signal Generator, 2.4GHz
Weinschel 8310 Series 6268 SmartStep? Attenuator Unit
Wiltron 6647A Programmable Sweep Generator w/ opt 03
Wiltron 6647A Programmable Sweep Generator w/opts 03/14
Wiltron 6709B-40 Signal Generator, 2 GHz
Yokogawa 2503-23 Digital AC Power Meter
Zero Products BNP65-600R&DC Media Blaster w/ Filter