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。

SWICHTEC INVENSYS ENERGY MAIN POWER BOARD 350-00079-01D DRG 21135 FOR R5800 ILPS
SWICHTEC INVENSYS ENERGY DRG 21592 CIRCUIT BOARD 350-00079-18B R5800 LCD DISPLAY
SWICHTEC INVENSYS ENERGY 350-0079-54C R5848-11 RECTIFIER CONNECTOR BOARD
SPARK MODULE, SM2 INVENSYS 120V. 3mA. A10006 - AMERICAN RANGE, BAKERS PRIDE   
SONDE INVENSYS DWT 0001
SM50 Intergy Invensys Supervisory Module
SIM-CCN GCM SIEBE Barber-Colman Invensys Carrier CCN Systems Integration Module
SIEBE PP-2446 PRESSURE TRANSDUCER BARBER COLMAN TAC INVENSYS ERIE
Siebe MSC-P-751 Environmental Controls Controller (Invensys?)
Siebe MSC-P1504-D Controller Lev-11 w/ AO & clock invensys robertshaw
Siebe MSC-NCM-D Controller invensys robertshaw
Siebe MSC-NCM Network Controller W/Modem MSCNCM Invensys
SIEBE INVENSYS MPC-8AI HVAC CONTROL, MULTI-PURPOSE CONTROLLER, ANALOG bbbbb - US
SIEBE INVENSYS MPC-4A0 MULTI-PURPOSE CONTROLLER, ANALOG OUTPUT MODULE -   w/G
Siebe Invensys MK-2690-0-0-2 VKS-9263-203-4-35 Actuator Valve Stainless Steel
Siebe GCM SIM-York GCM-86000 York Talk Invensys TAC Network 8000
SIEBE BARBER COLMAN INVENSYS 1/2" NPT 3-WAY CONTROL BLEND VALVE VS-9313-201-4-4
SIEBE BARBER COLMAN INVENSYS 1/2" NPT 2-WAY CONTROL BLEND VALVE VK-9211-201-4-3
Siebe Barber Coleman Invensys VK-7213-201-4-01 Valve Assembly 1/2" reduced port
Sensus Invensys ICE 5/8" by 5/8" Water Meter SRII BRAND   
SEALED   ! LAMBDA / INVENSYS POWER SUPPLY SE-500-3 SE5003
Scotsman Water Valve for CM250 120V 50/60hz 10W Invensys S-30 K-63916-12
Scotsman Water Valve 24V 60HZ 10W Invensys S-53N 283H11 K-67953
Scotsman Water Valve 24V 60HZ 10W INVENSYS K-76858
Scotsman 12-2548-01 Water Valve 24V 60HZ 10W Invensys 12-2548-01c
Schneider TAC Invensys Unit Ventilator Thermostat 2298-060    In Box
Schneider Invensys MP-495-0-2-2 Actuator 120V 50W .95A MP495022 50/60Hz
SCHNEIDER ELECTRIC, INVENSYS, TAC MN 150 LON CONTROLLER, SAT3 W/ROOFTOP PROFILE_
SCHNEIDER ELECTRIC, INVENSYS TAC MNL-V3R VAV CONTROLLER VAV MNL-V3RV2 PROFILE +_
Schneider Electric Invensys modulating valve AT13A00T Erie Pop Top
Schneider Electric Invensys diverting relay 4-20 PSIG set point 2325-502
Safetran Invensys DC to DC Converter A53106 9000-53106-0001 Rev E3
RX-19-36 ROBERTSHAW / INVENSYS FRYER THERMOSTAT FOR MILLIVOLTS RX1936 RX 19 36
ROTAVAL STAINLESS FEEDER W/ INVENSYS(.90HP) MOTOR AND RADICON GEAR  
Robertshaw Invensys Valve Model #P2
Robertshaw Invensys Range Temperature Dial Knob #4590-004
ROBERTSHAW INVENSYS MG21-1126 PRESSURE CONTROL (R2-4-24KD)
ROBERTSHAW INVENSYS GIST 100 - 320°C GRIDDLE THERMOSTAT GAS VALVE WITH IGNITION
Robertshaw Invensys Gas Thermostat,for Vulcan,Garland,Southbend #BJWA 25PC1-536
Robertshaw Invensys Gas Thermostat,3/8" FPT, #46-347
Robertshaw Invensys FD0-3-02-54 Gas Thermostat Model FD0, 461128 GARLAND   
Robertshaw Invensys Electric Thermostat,25A,250VAC,Max 325*F, #KP-87-60
Robertshaw Invensys Electric Thermostat KXT-466-36 175 to 500 Degree
Robertshaw Invensys Electric Thermostat KX-289-30 100 to 450 Degree
Robertshaw Invensys Electric Thermostat KX-289-30 100 to 450 Degree
Robertshaw Invensys Electric Thermostat 5110-052
Robertshaw Invensys Electric Oven Thermostat,30A,277VAC,Max Temp 325*F, #S-476-4
Robertshaw Invensys Electric Oven Thermostat,30A,277VAC,Max 450*F,#S-100-48
Robertshaw Invensys EA5-484-72 Electric Thermostat 180 degree max TST2528
Robertshaw Invensys Dual Solenoid Valve 3/8" FJT 120V #00497639-000G1
robertshaw invensys apl control. MC-20-1101 gard-pak III
Robertshaw Invensys Add-On Stuffing Box Kit For Capillaries #4650-001
Robertshaw Invensys 9920I Thermostat Heat Pump
Robertshaw Invensys 9801I Thermostat Gas Electric Oil Heat Pump
Robertshaw Invensys 9560 Thermostat Heat Pump
ROBERTSHAW INVENSYS 9025i REMOTE OUTDOOR SENSOR
Robertshaw Invensys 9020I Remote Sensor Indoor Use
Robertshaw Invensys 8625 Thermostat Gas Electric Oil Heat Pump
Robertshaw Invensys 8425 Thermostat Gas Electric Oil Heat Pump
Robertshaw Invensys 8401 Thermostat Gas Electric Oil Heat Pump
Robertshaw Invensys 700-705 Energy Cut Off Switch HT3 E
RobertShaw Invensys 60 to 250*F Electric Thermostat Assembly #5300-615
Robertshaw Invensys 41-1402 Hot Surface Furnace Ignitor
Robertshaw Invensys 41-1090 Hot Surface Furnace Ignitor Universal Kit
ROBERTSHAW GAS FRYER THERMOSTAT RX-1-36 MILLIVOLTS INVENSYS CATERING SPARES
Robertshaw Electric Thermostat S-224-24 5300-014 5300-01D 400 Degree Invensys
Robertshaw 5459-074 Invensys Thermostat BNP-404-64 BTP-404-60 288153
Robertshaw 5225-06G High Limit 440F/227C Thermosta Invensys LCC770240000   
Robertshaw 4020-007 Gas Safety Valve FMDA Invensys
Robertshaw 4020-005 Gas Safety Valve FMDA Invensys
Robert Shaw Thermostat Invensys 100-550°F - D1320605900
Robert Shaw / Invensys Gard-Pak 2 Solid State Motor Protector 3433-046
RELAY ELECTRIC PNEUMATIC HVAC INVENSYS 2364-211 R471-1    IN THE BOX
Reduzierung Typ EATON (INVENSYS) Durchflussrate 5,5l/min Druckbereich 1-10bar
RECEIVER CONTROLLER 2341-501 INVENSYS    IN THE BOX
Ranco Invensys L30-83 Solenoid Coil 24 VDC for V1-V12 Reversing Valve Heat Pump
Ranco / Invensys A30-181, ADAPTABLE REFRIGERATOR CONTROL
R2948 Intergy Invensys Rectifier Module
PROV-GCM Proview Programmer/Operator Keypad MMI Invensys Barber-Colman Siebe TAC
Pneumodular Diverting Relay Robertshaw Or Invensys 2353-501    In The Box
Pneumodular Diverting Relay Robertshaw Or Invensys 2353-501    In The Box
Pitco P5047588,Vulcan 410837-1, Invensys GSA60301800, Gas Thermostat 66-1017   
PEM-1 Invensys Barber Colman Siebe Packaged Equipment Module
PEM 1 BARBER COLMAN SIEBE INVENSYS TAC NETWORK 8000 PEM-1 PEM1 _
PEM 1 - BARBER COLMAN NETWORK 8000, SIEBE, INVENSYS, TAC
Peco/T.A.C./Invensys/Schneider Elec - TA-168-9 Manufacturer discontinued GREAT!!
P0917LYFPS40024 - FOXBORO - P0917LY FPS400-24 INVENSYS POWER SUPPLY  
ORIGINAL AC POWER ADAPTER FOR INVENSYS WONDERWARE KONTRON TUOCH PLANEL
NOS! INVENSYS DC TO FREQUENCY CONVERTER 7500-5016-1 750050161
NOS Invensys Valve Body 2-Way VB-7213-0-4-08 VB-7213-000-4-8 1" 14 CV
NOS Invensys Schneider Electric Valve bbbbage for Gear Train Actuators AV-390
NOS INVENSYS CONTROLS 10-250 SHANK EXTENSION 2"
NOS INVENSYS 2374-498 AIR SENSING SWITCH RSS-498
NIB Invensys Local Control Module Base Assembly LCMA 104-1-0-1 Barber Colman
  ! Ranco Invensys 13109 Motor Actuator 127-00022-001 (128) 12V 1/2"
  ! Invensys APV Actuator SW43T10A1E5 Divert Valve
   Whitton Brook Invensys Crompton Fuel Pump & Motor A-EF180MZ-D 8004-1064
   Thermostat by INVENSYS S-112-18 5300-09H 125 VA 120-270 VAC MT 400 F
   TAC INVENSYS PNEUMATIC ACTUATOR VALVE bbbbAGE KIT MK-2690 AV-400-0-0-1
   TAC Invensys MMC-420 Actuator Control Modules
   STATE-A.O. SMITH 9000547005 GAS CONTROL VALVE*INVENSYS/ROBERTSHAW
   SIEBE AT-523-11-1 RELAY REPAIR KIT INVENSYS BARBER-COLMAN
   Schneider Invensys Barber Colman Diaphragm Actuator MK Series 6" x 4.5"
   ROBERTSHAW INVENSYS MINI-GARD PRESSURE CONTROL MG20-1098 MPL-7003 3100-051
   Robertshaw Invensys INT-43 10-546 Add-A-Wire Thermostat Wiring Adapter
   ROBERSHAW-INVENSYS VS 4010-001 SAFETY VALVE-COMMERCIAL*FMC*NLA/Obsolete
   Overstock Invensys Controls Heavy Duty Refrigerant Hose 48" 1290132-B48
   Overstock Invensys Controls Heavy Duty Refrigerant Hose 36" 1290132-B18
   Overstock Invensys Controls Heavy Duty Refrigerant Hose 24" 1290132-B24
   Overstock Invensys Controls Heavy Duty Refrigerant Hose 18" 1290132-B18
   Open Box INVENSYS 3PSI-15PSI GAUGE 250-3074
   OLD INVENSYS PRESSURE TRANSMITTER 0-6IN H2O 863DPM2D1NKMP FOXBORO GG
   listing    Invensys RKS-2001-0-1 Receiver Controller.   
   listing    Invensys Foxboro D0135ND Electric Level Sensor ORIGIN 2A8716 C0-NI G/M
   listing    Foxboro P0916FL Rev C 32ft Length Cable I/A Series PLC Invensys PO916FL 32'
   listing    Foxboro P0916DY Rev B 32ft Length Cable I/A Series PLC Invensys PO916DY 32'
   listing    Foxboro P0916DE Rev C 32ft Length Cable I/A Series PLC Invensys PO916DE 32'
   listing INVENSYS TC-4252 ELECTRIC BULB THERMOSTAT 2 STAGE M & M CONTROL
   listing Invensys Barber Colman CP-8552 Transducer
   listing Invensys Auxiliary Switch Kit - 2 Spot Switches -   !
   listing Foxboro P0916FL Rev C 18.5ft Length Cable I/A Series PLC Invensys PO916FL 18.5'
   listing Foxboro P0916FK Rev C 18.5ft Length Cable I/A Series PLC Invensys PO916FK 18.5'
   listing Foxboro P0916FK Rev B 18.5ft Length Cable I/A Series PLC Invensys PO916FK 18.5'
   listing Foxboro P0916FJ Rev C 10ft Length Cable I/A Series PLC Invensys PO916FJ 10'
   listing Foxboro P0916DX Rev B 18.5ft Length Cable I/A Series PLC Invensys PO916DX 18.5'
   listing Foxboro P0916DE Rev C 32ft Length Cable I/A Series PLC Invensys PO916DE 32'
   listing Foxboro P0916DD Rev C 18.5ft Length Cable I/A Series PLC Invensys PO916DD 18.5'
   listing Foxboro P0916DD Rev B 10ft Length Cable I/A Series PLC Invensys PO916DD 10'
   listing FOXBORO ECKARDT INVENSYS 139PP-ASEC5 PNEUMATIC PRESSURE REPEATER   
   listing Eurotherm Invensys Barber-Colman Ea22 120v Actuator
   listing BARBER COLMAN SIEBE INVENSYS TAC NETWORK GCM - 86120
   INVENSYS-ROBERTSHAW VC 4220-013 COMMERCIAL OVEN THERMOSTAT*NLA/OBSOLETE
   INVENSYS-ROBERTSHAW 700-101 MANUAL GAS VALVE