选型注意事项

  S7-300PLC的选型原则是据生产工艺所需的功能和容量进行选型，并考虑维护的方便性、备件的通用性，以及是否易于扩展和有无特殊功能等要求。选型时具体注意以下几方面：

  (1)有关参数确定。一是输入/输出点数(I/O点数)确定。这是确定PLC规模的一个重要依据，一定要根据实际情况留出适当余量和扩展余地。二是PLC存储容量确定。注意当系统有模拟量信号存在或要进行大量数据处理时，其存储容量应选大一些。

  (2)系统软硬件选择。一是扩展方式选择，S7-300PLC有多种扩展方式，实际选用时，可通过控制系统接口模块扩展机架、Profibus-DP现场总线、通信模块、运程I/O及PLC子站等多种方式来扩展PLC或预留扩展口;二是PLC的联网，包括PLC与计算机联网和PLC之间相互联网两种方式。因S7-300PLC的工业通信网络淡化了PLC与DCS的界限，联网的解决方案很多，用户可根据企业的要求选用;三是CPU的选择，CPU的选型是合理配置系统资源的关键，选择时必须根据控制系统对CPU的要求(包括系统集成功能、程序块数量限制、各种位资源、MPI接口能力、是否有

  PROFIBUS-DP主从接口、RAM容量、温度范围等)，并好在西门子公司的技术支持下进行，以获得合理的选型;四是编程软件的选择，这主要考虑对CPU的支持状况，我们的体会是：STEP7V4.0对有些型号的CPU不支持，硬件组态时会发生故障出错，而STEP7V5.0则不存在这种问题。

  二、设计及使用注意事项

  1. 设计注意事项

  设计时主要应注意以下几方面：

  (1)PLC输出电路中没有保护，因此在外部电路中应设置串联熔断器等保护装置，以防止负载短路造成PLC损坏。熔断器容量一般为0.5A。

  (2)PLC存在I/O响应延迟问题，因此在快速响应设备中应加以注意。MPI通信协议虽简单易行，但响应速度较慢。

  (3)编制控制程序时，好用模块式结构程序。这样既可增强程序的可读性，方便调试和维护工作;又能使数据库结构统一，方便WinCC组态时变量标签的统一编制和设备状态的统一显示。

  (4)硬件资源。要合理配置硬件资源，以提高系统可靠性。如PLC电源配电系统要配备冗余的UPS不间断电源，以排除停电对全线运行的不利影响。又如对电机的控制回路要进行继电器隔离，以消除外部负载对I/O模块的可能损坏。另外，系统设备要采用独立的接地系统，以减少杂波干扰。

 pcs honeywell RA890F1304 Combustion controller
1 pcs honeywell RA890G1245 Combustion controller
1 pcs honeywell S7800A1001
1 PCS Honeywell TC-PCIC02 Mainboard
1 PCS Honeywell-Yamatake  J-UDM00 tested
1 PCS Honeywell-Yamatake J-AOM10 tested
1 PCS Honeywell-Yamatake J-PIM00  tested
1 PCS Honeywell-Yamatake J-PIM00 tested
1 PCS Honeywell-Yamatake J-UDM00 tested
1 PCS NEW  Honeywell PTSRB0101A2
1 PCS NEW Honeywell PTSRB0101A2
1 product rating-  1PC NEW Honeywell PUB6438SR programmable controller
1 product rating- 100% Tested Honeywell TC-0DJ161 60-Day Warranty [3ik]
1 product rating- 113228 Honeywell Honeywell U.V. Sensing Tube OEM 113228
1 product rating- 1PC New Honeywell M4185B1058 M4185B1058 1 year warranty#XR
1 product rating- 1PC NEW Honeywell PUB6438SR programmable controller one year warranty#XR
1 product rating- 1PC NEW Honeywell PUL4024S controller one year warranty#XR
1 product rating- Brand New Honeywell RM7823 A 1016 RM7823A1016 Burner Control 1 year warranty
1 product rating- Brand New In Box Honeywell RM7823 A 1016 Burner Control 1 year warranty
1 product rating- Full Tested Honeywell TC-0DJ161 60Day Warranty [mc1]
1 product rating- Full Tested Honeywell TC-0DJ161 60-Day Warranty [tsz]
1 product rating- Honeywell 12335 Actuator Modulating 4/20ma 90/160 Strk 30/60 Second 150Lb-In Tr
1 product rating- Honeywell 2312 M9174C1025 120vAdjT/S 2sw 75#PropMtr 120vAdjT/S 2sw 75#PropMtr
1 product rating- Honeywell 51304754-150 high level analog bbbbb module
1 product rating- Honeywell 51304754-150 MC-PAIH03 High Level Analog bbbbb Processor
1 product rating- HONEYWELL F300E1019 / F300E1019 (BRAND NEW)
1 product rating- HONEYWELL M4185B-1058 / M4185B1058 (BRAND NEW)
1 product rating- HONEYWELL M7284A1012 ACTUATOR MODUTROL MOTOR 30-60SECS 160DEGREE STROKE-FREESHIP
1 product rating- HONEYWELL M7285A-1003 / M7285A1003 (NEW IN BOX)
1 product rating- HONEYWELL M9182A-1011 / M9182A1011 (BRAND NEW)
1 product rating- Honeywell R7249A 1003 Control 286R
1 product rating- HONEYWELL R7249A1003 FLAME SAFETY AMPLIFIER *USED*
1 product rating- HONEYWELL R7847B-1031 / R7847B1031 (BRAND NEW)
1 product rating- HONEYWELL R7861A-1026 / R7861A1026 (BRAND NEW)
1 product rating- HONEYWELL R7861A-1026 DYNAMIC SELF CHECK ULTRAVIOLET FLAME AMPLIFIER -FREE SHIP
1 product rating- HONEYWELL RA890 G 1260 SOLID STATE ELECTRONIC FLAME SAFEGUARD PROTECTOR 120V
1 product rating- Honeywell RA890G1260 Protectorelay Flame Safeguard RA890G 120V 50/60HZ
1 product rating- HONEYWELL RM7885A-1015 / RM7885A1015 (NEW IN BOX)
1 product rating- HONEYWELL SK5208 / SK5208 (USED TESTED CLEANED)
1 product rating- HONEYWELL V4055A-1080 / V4055A1080 (BRAND NEW)
1 product rating- HONEYWELL V4055D-1001 / V4055D1001 (BRAND NEW)
1 product rating- HONEYWELL V5055A-1053 / V5055A1053 (BRAND NEW)
1 product rating- HONEYWELL V51E-1018 / V51E1018 (BRAND NEW)
1 product rating- HONEYWELL W7751B-2002 / W7751B2002 (USED TESTED CLEANED)
1 product rating- HONEYWELL W973A-1017 / W973A1017 (USED TESTED CLEANED)
1 product rating- HONEYWELL XC-5010-C / XC5010C (USED TESTED CLEANED)
1 product rating- ML6425A3022 Honeywell Dirmntv/A,Sr-Stmdwn,3/4"Stroke OEM ML6425A3022
1 product rating- ML7425B3012 Honeywell Dirmntv/A,Sr-Stmup,0/2-10Vdc OEM ML7425B3012
1 product rating- New Genuine HONEYWELL M7284A1012 Damper Actuators Motor Burner
1 product rating- NEW Honeywell M7284A1012 Damper Actuators Motor Burner
1 product rating- NEW IN BOX Honeywell M4185B1058 M4185B1058 1 year warranty
1 product rating- New In Box HONEYWELL M7284A1012 Damper Actuators Motor Burner
1 product rating- NEW IN BOX Honeywell PUB6438SR programmable controller one year warranty
1 product rating- NEW IN BOX Honeywell PUL4024S controller one year warranty
1 product rating- T991A1061 Honeywell 160/260F Prop.Temp.Ctrl 5'Cap OEM T991A1061
1 product rating- USED HONEYWELL BURNER CONTROL RM7838B1013,R7849B1021,ST7800A1088,Q7800A1005 BY
1 product rating- V4055A1007 Honeywell Actuator 120V 26 Sec.-Open OEM V4055A1007
100% NEW Honeywell M7284A 1004 in box
100% NEW Honeywell M7284C 1000 in box
100% NEW Honeywell M7284Q1009 Servo Drive in box
100% NEW Honeywell M9484D1010 Servo MOTOR in box
100% NEW Honeywell ML7421A1032-E in box
100% NEW Honeywell R4343D1017 in box
100% NEW Honeywell RA890F 1304 in box
100% NEW Honeywell RA890G 1245 in box
100% NEW Honeywell RP7517A1009 in box
100% Tested Honeywell TC-0DJ161 60-Day Warranty [3ik]
113228 Honeywell Honeywell U.V. Sensing Tube OEM 113228
122037 Honeywell 100 Psi Quartz bbbbbb,C7012A,F OEM 122037
13 product ratings- 1 PC New Honeywell S7800A-1001 S7800A1001 Keyboard Display Module
13 product ratings- 1PC Brand New Honeywell RM7895A1014 One year warranty free Shipping
13 product ratings- 1PC Brand New Honeywell RM7895A1014 Quality assurance fast delivery
13 product ratings- 1PC Brand New Honeywell S7800A 1001 display panel 1 year warranty DHL free Ship
13 product ratings- 1PC New Brand Honeywell S7800A 1001 One year warranty Fast Delivery
13 product ratings- 1PC New Honeywell RM7895A 1014 One year warranty RM7895A1014 Fast Delivery
13 product ratings- 1PC NEW Honeywell RM7895A1014 Primary Control Burner Control FREE SHIIPING#XR
13 product ratings- 1PC New in box Honeywell Controller S7800A 1001 1 year warranty Fast Delivery
13 product ratings- 1PC New in box Honeywell RM7895A 1014 One year warranty RM7895A1014 FastDelivery
13 product ratings- 1PC New in box Honeywell S7800A 1001 One year warranty Fast Delivery
13 product ratings- Brand New H1ywell RM7895A 1014 RM7895A1014 Expedited shipping
13 product ratings- Brand New Honeywell RM7895A1014 One year warranty fast delivery RM7895 A 1014
13 product ratings- HONEYWELL S7800A-1001 / S7800A1001 (BRAND NEW)
138166 Honeywell Microamp Scale Only Meter OEM 138166
14004139-001 Honeywell bbbbbbbberkit,Mp953A-E,3/4"Str OEM 14004139-001
14004140-001 Honeywell Positnerkit,1 1/2"Strk,8"&13" OEM 14004140-001
14004214-001 Honeywell bbbbbbbberkit,3/4"Strk,5"Act OEM 14004214-001
14004264-001 Honeywell Mp918A Repairkitinclbbbbbbbber OEM 14004264-001
1P Used HONEYWELL 51304386-150 fast delivery
1P Used Honeywell C7061A 1020 tested Fully C7061A1020 Fast Delivery
1P Used Honeywell XC 5010 C XC5010C Fast delivery
1pc   Honeywell-Yamatake J-PIM00
1PC  NEW  Honeywell Field Controller PUL6438S
1PC  NEW HONEYWELL BURNER CONTROL EC7823A1004
1PC  used  Honeywell 51402573-250
1pc  used  Honeywell CP-DIO
1PC 50126981-001 Honeywell High Perbbbbance 8620 Ring Scanner BarCode Scanner
1PC 50126981-001 Honeywell High Perbbbbance 8620 Ring Scanner BarCode Scanner#XR
1PC 51304419-150 | MC-IOLX02 HONEYWELL I/O bbbb Extender Module
1PC Brand New H1ywell 900A01-0102 900A010102 Expedited shipping
1PC Brand New H1ywell 900B01-0101 900B010101 Expedited shipping
1PC Brand New H1ywell EC7850A 1072 EC7850A1072 Expedited shipping
1PC Brand New H1ywell RM7890B1014 RM7890B1014 Expedited shipping
1PC Brand New Honeywell 142PC01D One year warranty fast delivery
1PC Brand New Honeywell 142PC01D One year warranty free Shipping
1PC Brand New Honeywell 142PC01D Quality assurance fast delivery
1PC Brand New HONEYWELL analog bbbbb module XFL521B
1PC Brand New Honeywell BW Technologies MCXL-XWHM-Y-NA 1 year warranty
1PC Brand New Honeywell Controller XCL5010 One year warranty
1pc Brand New Honeywell EC7823A1004 Burner Controller 1 year warranty
1pc Brand New Honeywell EC7823A1004 Burner Controller DHL free shipping
1PC Brand New Honeywell EC7823A1004 One year warranty fast delivery
1PC Brand New Honeywell EC7823A1004 One year warranty free Shipping
1PC Brand New Honeywell EC7850A1072 One year warranty fast delivery
1PC Brand New Honeywell EC7850A1072 One year warranty free Shipping
1PC Brand New Honeywell EC7850A1080 Quality assurance fast delivery
1PC Brand New Honeywell FEMA pressure switch DWR06
1PC Brand New Honeywell FEMA pressure switch DWR1
1PC Brand New HONEYWELL bbbbb module XFL823A
1PC Brand New HONEYWELL bbbbb module XFL824A
1PC Brand New Honeywell M784Q 1009 M784Q1009 1 year warranty
1PC Brand New Honeywell M784Q 1009 M784Q1009 M784Q1009 1 year warranty
1PC Brand New Honeywell M784Q 1009 M784Q1009 M784Q1009 1 year warranty#XR
1PC Brand New Honeywell ML7421A8035-E electric valve actuator drive
1PC Brand New Honeywell ML7421A8035-E electric valve actuator drive
1PC Brand New Honeywell MMG810.1 Quality assurance fast delivery
1PC Brand New Honeywell RM7840L-1018
1PC Brand New Honeywell RM7840L-1018 One year warranty fast delivery
1PC Brand New Honeywell RM7840L-1018 One year warranty fast delivery#XR
1PC Brand New Honeywell RM7840L-1018 One year warranty free Shipping
1PC Brand New Honeywell RM7840L-1018 Quality assurance fast delivery
1PC Brand New Honeywell RM7890A 1015 Combustion safety controller DHL free Ship
1PC Brand New Honeywell RM7895A1014 One year warranty free Shipping
1PC Brand New Honeywell RM7895A1014 Quality assurance fast delivery
1PC Brand New Honeywell S7800A 1001 display panel 1 yea