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。

Woodward SPM-A synchonizer 9907-029 REV.B
Woodward SPM-A synchonizer 9907-018 Rev. C
WOODWARD SPM-A (9905-001) SYNCHRONIZER WITH MANUAL 
WOODWARD SPM SYNCHRONIZER, PN 8272-385, 
WOODWARD SPM SYNCHRONIZER, PN 8271-610, EXC COND
Woodward SPM Synchronizer Model 8271-607A NNB
WOODWARD SPM SYNCHRONIZER 8272-190-C
Woodward Speed Setting Potentiometer Bracket Assembly 5438-121 NOS
WOODWARD SOLENOID VALVE 8402-238
WOODWARD SOLENOID VALVE 8402-214 5852-159
WOODWARD SOLENOID VALVE 5852-130
WOODWARD SOLENOID VALVE 5852-130
WOODWARD SOLENOID SYNCHRO-START # SA-3187 NSN: 5945-01-280-5477 # 1503-24C6U4BS
WOODWARD SOLENOID PART # SA-1637-24 NSN: 5945-01-048-9774
Woodward Servo Postion Controller 8200-226 Rev B
Woodward SEG IRD1-G Transbbbbator Differezialschutz
woodward rotary direct drive vallve
WOODWARD RESISTOR ASSEMBLY # 9900-350 NSN: 5905-01-290-0002
Woodward PWM Gas Trim Valve P/N 8235-622
Woodward PVC Single Receptacle W/Hinged Cover #50-1651 15A 120V Twist Lock ()
WOODWARD PROTECH 203 OVERSPEED PROTECTION SYSTEM 9907-149 ()
Woodward ProTech 203 Overspeed Protection System 9905-990 Rev G With Key
Woodward ProTech 203 Overspeed Protection System 9905-990 Rev G No Key
Woodward Protech 203 Overspeed Protection System 9905-990 Rev G Missing 2 PS
Woodward Protech 203 Overspeed Protection System 8200-203 Rev N
WOODWARD PROTECH 203 OVERSPEED PROTECTION PN 9905-995
WOODWARD PROTECH 203 OVERSPEED PROTECTION PN 8200-301
WOODWARD PROCESS/IMPORT-EXPORT CONTROL, PN 9905-090, EXC COND
WOODWARD Process Import-Export Control (Part #9905-090 H) EXC COND
WOODWARD PREREGULATOR FUSE 3AG.75AMP
Woodward PM Motor Control 8272-536 
Woodward Piston Part # 3525-039
WOODWARD PGD GOVERNOR A8556-749 PS, 320-600 RPM, S/N: 1111611 (REFURBISHED)
WoodWard PG Lever Governor S/N: 420991
WOODWARD PEAK 150 DIGITAL STEAM TURBINE CONTROLLER 9905-867 REV-J NNB
Woodward Part # 8272-288 0 Load Sharing Speed Controller 2301A
Woodward Netcon 5000 bbbbb Module 5464-333
WOODWARD NETCON 5000 DISCREET OUTPUT MODULE, EXC COND
WOODWARD NETCON 5000 CPU MODULE, , EXCELLENT COND
WOODWARD NETCON 5000 ACTUATOR DRIVER OUTPUT MODULE,EXC
WOODWARD NETCON 5000 (PART # 5464-588) SERIAL #11459522
WOODWARD MOTOR OPERATED POTENTIOMETER P/N 9900-229 NSN 5905-01-086-2714
Woodward Module 5466-409
WOODWARD MILITARY PGD DIAL GOVERNOR; P/N: 9900-149 ~~GOV~SURPLUS~
WOODWARD MILITARY PG DIAL GOVERNOR; P/N: 9900-149 ~~SURPLUS~
WOODWARD MILITARY P.G. DIAL GOVERNOR; P/N: 9900-149 ~~SURPLUS~
Woodward MFR 11 Multifunktionsrelais Netzüberwachungsrelais Netzüberwachung NEU
Woodward MFR 1 RELAY
Woodward Master Synchronizer and Load Control 9907-004 Rev N
Woodward Master Synchronizer and Load Control 9905-797 Rev M
WOODWARD LOAD SHARING AND SPEED CONTROL, PN 9905-068, EXC COND
WOODWARD LOAD SHARING AND SPEED CONTROL, PN 8272-288, /UN
WOODWARD LOAD SHARING AND SPEED CONTROL 8271-652, EXC COND
WOODWARD LOAD SHARING AND SPEED CONTROL 8271-467, EXC COND
Woodward Industrial Turbine Fuel Control Valve Driver 8200-216
Woodward Hydraulic Governor pn.5178938
Woodward HRT Inc. - Stainless Steel Hydraulic Service Plug - P/N: 41001748 (NOS)  Charity item
WoodWard Governors (3) UG 8 (1) PG Lever
WOODWARD GOVERNOR, 8561-252, PSG, 5101888, DETROIT DIESEL
Woodward Governor w/ Bodine Electric Co Motor for Detriot Diesel - P/N: 8561-537
WoodWard Governor UG 8
Woodward Governor Type UG-8 PN: 34381 NOS
WOODWARD GOVERNOR TYPE PG-PL PUMP CONTROL 8552-674, 
WOODWARD GOVERNOR TURBINE ELECTRICAL CONTROL ASSEMBLY, MODEL 8230-621
WOODWARD GOVERNOR TM-100 DIGITAL DRIVER DUAL 8200-150
WOODWARD GOVERNOR SPEED SETTING PISTON 361324
WOODWARD GOVERNOR SG GOVERNOR P/N 8511-453 /UN
Woodward Governor Piston Rod P/N 364521
Woodward Governor Piston & Rod P/N 3561-073, 9987-878 NOS
Woodward Governor PG-PL PGPL 8572-565 Un Large Engine Generator Turbine
Woodward Governor PG-PL P/N 8572-212 Waukesha P/N 295493 Brand  In Box
Woodward Governor Part # 8240-005 Serial # 1088064 
Woodward Governor P/N A8240-449 Diesel Engine REMANUFACTURED
Woodward Governor P/N A8240-298 Diesel Engine 
Woodward Governor P/N 1247-007 Connector
Woodward Governor Oil Gauge Site Glass 1832-109 NOS
Woodward Governor Gas Shutoff Valve 9905-451
Woodward GOVERNOR for Military generator p/n 8561-301, 371156, 2990-00-085-5624
Woodward GOVERNOR for Military 100KW Cat Generator MEP007A D333C p/n 8510-212
WOODWARD GOVERNOR FLOW CALIBRATED VALVE CONTROL DIESEL GENERATOR 5233-507 
Woodward Governor Field Terminal Module 5437-080
Woodward Governor Field Terminal Module 5437-079
Woodward Governor Field Terminal Module 5437-052
Woodward governor EGB-13P, PN: 8540-381
Woodward Governor EGB-13P, PN: 8240-381
WOODWARD GOVERNOR DYNA-CONTROLLER PART NUMBER 8270-1010
WOODWARD GOVERNOR DPG-2401-002 CUMMINS EFC ACTUATOR
WOODWARD GOVERNOR CONTROL SA-3682-AN-2 SPEED SWITCH
WOODWARD GOVERNOR CONTROL PANEL 8271-353 2301 SPEED SENSOR NOS
Woodward Governor Company 5503-267 RT S/0 Module Netcon IIIB 3 9 pin
Woodward Governor Company 5466-353 Rev. A Transceiver Module
Woodward Governor Company 5464-643 Rev. D D/I Module
Woodward Governor Company 2201 5417-038 Rev A 6’ Cable
Woodward Governor Company - Speed Adjusting Sleeve - P/N: 040323 (NOS)  Charity item
Woodward Governor Company - Speed Adjusting Sleeve - P/N: 040323 (NOS)  Charity item
WOODWARD GOVERNOR BASE # 4008-517 NSN: 2990-01-033-7530
Woodward Governor Actuator EG1P ( EG-1P) E8250-826
WOODWARD GOVERNOR 8577-102 US 104816
Woodward Governor 8512-133
WOODWARD GOVERNOR 8272-164  8272164
WOODWARD GOVERNOR 8271-468 D **
WOODWARD GOVERNOR 8 CHANNEL RELAY MODULE P/N 5441-673
Woodward Governor 5466-258 Module Simplex Discrete I/O
WOODWARD GOVERNOR 5462-757 C Indicator Board
WOODWARD GOVERNOR 5 AMP RELAY INTERFACE P/N 5441-637
WOODWARD GOVERNOR 28 CHANNEL RELAY MODULE P/N 5441-407
Woodward Governor / 5441-693 Module 24 IN 12 OUT
Woodward Governor / 5417-178 CABLE MICRONET HIGH DENSITY ANALOG/DISCRETE
Woodward Governor / 5417-045 NETCON 20 FT DISCRETE W/ BACKS
Woodward Governor / 5417-033 NETCON LOW DENSITY ANALOG BLACK
Woodward Governor - 8239-082 Rev E - Load Sharing Interface Module
Woodward Governor - 5466-353 Rev C - Transceiver Module
Woodward Governor - 5464-544 Rev E - 4 Channel Actuator Control Module
Woodward Governor - 5464-414 Rev NW - Speed Sensor Module
Woodward Governor - 5464-414 Rev B - Speed Sensor Module
Woodward Governor - 5464-211 Rev D - 2 Channel Actuator Control Module
Woodward Governor - 5464-210 Rev D - 2 Channel Actuator Control Module
Woodward Governor - 5464-132 Rev B - FC198 Co-Pro
Woodward Governor - 5464-013 Rev G - RTD bbbbb Module
Woodward Governor - 5463-785 Rev J - Isolated 4-20 mA Analog bbbbb Module
Woodward Governor - 5463-581 Rev H - 8 Channel Isolated 4-20 mA bbbbb Module
Woodward Governor - 5463-473 Rev D - DCS 4.4 SIO OPSYS Module
Woodward Governor - 5461-655 Rev H - Fuel Valve Final Driver Module
Woodward Governor - 5461-648 Rev F - 2 Channel Actuator Control Module
Woodward Governor - 5437-092 Rev F - Netcon Expansion Chassis Power Supply
Woodward Governor - 5437-079 Rev A - Field Terminal Module
Woodward Governor - 5417-028 Rev A - Cable
Woodward Governor
WOODWARD GOVERNER STRAIGHT SHAFT # 032487 NSN: 3040-01-198-1072
Woodward Governer Company Control Board # 8270-238 ( 671 or 971 diesel motor )
Woodward Governer Co Import Control 8271-570
WOODWARD GOVENOR P.G.A. DRIVE SPEED 300-960RPM NICE
WOODWARD GENERATOR LOADING CONTROL 8271-488 D
WOODWARD GENERATOR LOAD SENSOR MODEL 8290-048 F -- CLEAN
WOODWARD GENERATOR LOAD SENSOR 8290-048 // 3074-47IC
Woodward Generator Diesel Engine Speed Governor UG8 420-1255 RPM
Woodward Generator Diesel Engine Speed Governor UG8 350/375-1255 RPM (2)
Woodward Generator Controller MFR1 Diesel Controller Monitor MFR15 8440-1771
Woodward GENERATOR 9907-021 Rev.  2301A Load Sharing And Speed Control
Woodward Gas Shutoff Valve P/N 9905-891 2" Warranty Fast Shipping
Woodward Fuel Valve Liquified Turbine 771-615-90001 or 8004-230 Fuel Control
WOODWARD FINAL DRIVER, PN 8230-815, EXC COND
WOODWARD EXPLOSION PROOF SOLENOID VALVE 5852-149
Woodward Ethernet Interface FTM 5453-754
Woodward EPG Speed Control Steuergerät 8290-045 Rev. E1 --
Woodward Engine- Governor- UG8
Woodward Engine Governor 8290-205 EPG Speed Control
WoodWard Electro-Mechanical Linear Actuator 10202-000-0-24 30KW 60KW Generator
Woodward Electrical Governor Actuator #8250-570 42 Degrees (NIB)
Woodward Electrical Governor Actuator #8250-570 42 Degrees (Factory Re-Furbished
WOODWARD EG-M CONTROL P/N 8270-916  SURPLUS
Woodward EGCP-2 8406-120 Rev G Generator Control Panel Digital - CAT
Woodward EG-A Governor Controller #9908-003 120 VAC 50/60 Hz
Woodward EG-10P Actuator 9900-294
Woodward EG Remote Sump Motor Assy 8250-390 Servo 8250-102 Actuator AR9900-217GH
Woodward EG Remote Actuator AR9900-217GH for use with 8250-102
WOODWARD EASYGEN-1000 
Woodward Easygen 3000 Genset Controller 8440-1831H
WOODWARD DYNA SPEED CONTROLLER 10502-001 8270-1096 GOVENOR CONTROL BOX
WOODWARD DYNA 8000 ELECTRONIC GOVERNOR SYSTEMS 24 VOLT MECHANICAL ACTUATOR
Woodward DSM Synchroniser 8239-002
Woodward Drehzahlregler für Deutz S/BA/M 528 Schiffsmotoren
woodward digital synchronizer and load control 9905-797
WOODWARD DIGITAL REMOTE FINAL DRIVER 8239-006
WOODWARD DIGITAL REMOTE FINAL DRIVER (DRFD) PN 8239-005
Woodward Digital Remote Final Driver (DRFD) 8239
WOODWARD DIGITAL REFERENCE UNIT 8272-683 ELECTRONIC CONTROL OF SIGNAL VOLTAGE
WOODWARD DIGITAL REFERENCE UNIT 8272-683 ELECTRONIC CONTROL OF SIGNAL VOLTAGE
Woodward Dental Extracting Forceps 3FS Lower Molars
Woodward Dental Extracting Forceps 3FS Lower Molars
Woodward C8516-040 4500 RPM TG Governor NIB
Woodward Automatic Power Transfer and Load Control 9905-007 PARTS/REPAIR
Woodward Automatic Power Transfer and Load Control 9905-007 N 
WOODWARD AUTOMATIC POWER TRANSFER AND LOAD CONTROL 9905-007
Woodward Automatic Power Transfer and Load Con 9905-007
WOODWARD AUTOMATIC GENERATOR LOADING CONTROL, PN 9905-096, EXC COND
Woodward Automatic Generator Loading Control 9905-096 H - 
WOODWARD AUTOMATIC GENERATOR LOADING CONTROL 9905-096
WOODWARD AUTO POWER TRANSFER & L.C., 9905-007 / 171-057
Woodward Atlas Controller w/Profibus Module
WOODWARD A8556-749 PS GOVERNOR, 300-650 RPM, S/N: 2208540 (REFURBISHED)
WOODWARD 9907-838  9907838
WOODWARD 9907-252  9907252
WOODWARD 9907-252  9907252
WOODWARD 9907-029  9907029
Woodward 9907-029 Rev E - SPM-A Synchronizer *Gebraucht*
WOODWARD 9907-028  9907028
Woodward 9907-028 SPM-A Synchronizer Load Sharing Module 115/230V / Warranty
Woodward 9907-028 Revision F SPM-A SYNCHRONIZER
Woodward 9907-028 Revision D SPM-A SYNCHRONIZER
WOODWARD 9907-027  9907027
Woodward 9907-018 Rev. C 2301 A Load Sharing and Speed Control  Good
Woodward 9907-005 Rev. G Master Synchronizer & Load Control
WOODWARD 9907-005  9907005
WOODWARD 9905-971  9905971
WOODWARD 9905-970  9905970
WOODWARD 9905-969  9905969
Woodward 9905-797 Digital Synchronizer and Load Control Rev B
WOODWARD 9905-796  9905796
WOODWARD 9905-795  9905795
WOODWARD 9905-760  9905760
Woodward 9905-711 Rev. L Digital Synchronizer and Load Control DSLC
Woodward 9905-708 Digital Synchronizer and Load Control Rev L
WOODWARD 9905-373  9905373
Woodward 9905-373 Rev. T Digital Synchronizer and Load Control DSLC
Woodward 9905-373 Rev. T Digital Synchronizer and Load Control DSLC
WOODWARD 9905-367  9905367
WOODWARD 9905-204A DSM DIGITAL SPEED MATCHING SYNCHRONIZER 120V-AC 6A B240206
WOODWARD 9905-111  9905111
WOODWARD 9905-096  9905096
WOODWARD 9905-096 J AUTOMATIC GENERATOR LOADING CONTROL  GOOD TAKEOUT
Woodward 9905-096 Automatic Generator Loading Control 9905096 Rev. J 115 230 VAC
WOODWARD 9905-096 / 9905-096J / J / AUTOMATIC GENERATOR LOADING CONTROL
WOODWARD 9905-092  9905092
WOODWARD 9905-092 / 9905-092K / K / PROCESS IMPORT EXPORT CONTROL
WOODWARD 9905-068C  9905068C
WOODWARD 9905-068  9905068
WOODWARD 9905-068 / 9905-068B / B