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。

 NIB VEXTA C8384-9212H C83849212H STEPPING MOTOR 2 PHASE 1.8* / STEP 4.4A 2.5V
1 PC  VEXTA RKD514L-C servo drive Tested
1 PC Used AXHD15K VEXTA stepper driver
1 PC Used AXHD30K VEXTA stepper driver
1 PC Used VEXTA Dongfang Motor Vibration Damper D6CL-6.3F
1 PC Used Vexta Oriental Motor UDK5107N In Good Condition
1 PC Used Vexta PCB AXHD100K In Good Condition
1 PC Used Vexta UDK5114N In Good Condition
1 PC VEXTA RKD514L-C servo drive Tested
1 PC VEXTA Servo Drive RKD514L-A Tested
1 PC VEXTA Stepper Motor Driver RC-204A Tested
1 PCS   VEXTA stepper driver   CSD5814N   tested
1 PCS   VEXTA stepper driver  CSD2112-P   tested
1 PCS   VEXTA stepper driver  CSD2120-P   tested
1 PCS   VEXTA stepper driver  CSD2120P2   tested
1 PCS   VEXTA stepper driver  CSD5814N-P   tested
1 PCS   VEXTA stepper driver CMD2112P   tested
1 PCS   VEXTA stepper driver CSD5807N    tested
1 PCS   VEXTA stepper driver CSD5807N-P  tested
1 pcs  VEXTA   Motor SD5107P2  tested
1 pcs  VEXTA  Motor PK243A1-SG10  tested
1 pcs  VEXTA drive SD5107 board  Tested
1 PCS NEW IN BOX VEXTA Oriental Governor TMP-1
1 pcs used Dongfang VEXTA stepping motor driver 2-PHR5E DRIVER UD2115B
1 pcs VEXTA 2.8A CSD2120-P   stepper motor driver tested
1 pcs VEXTA 2.8A CSD2120-P stepper motor driver tested
1 pcs VEXTA CSD5807N-P 0.75A   stepper motor driver tested
1 pcs VEXTA CSD5807N-P 0.75A stepper motor driver tested
1 pcs VEXTA CSD5814N-P    stepper motor driver tested
1 pcs VEXTA CSD5814N-P stepper motor driver tested
1 pcs VEXTA drive SD5107 board Tested
1 PCS VEXTA five-phase stepper driver DFC5103P in good condition
1 PCS VEXTA five-phase stepper driver UDX5107N 0.75A 100V in good condition
1 pcs VEXTA Motor PK243A1-SG10 tested
1 pcs VEXTA Motor SD5107P2 tested
1 PCS VEXTA Oriental BLHD15K DC24V Brushless DC Motor Driver in good condition
1 PCS VEXTA Oriental driver AXHD15K in good condition
1 PCS VEXTA stepper driver CMD2112P tested
1 PCS VEXTA stepper driver CSD2109-P in good condition
1 PCS VEXTA stepper driver CSD2112-P tested
1 PCS VEXTA stepper driver CSD2120-P tested
1 PCS VEXTA stepper driver CSD2120P2 tested
1 PCS VEXTA stepper driver CSD5807N tested
1 PCS VEXTA stepper driver CSD5807N-P tested
1 PCS VEXTA stepper driver CSD5814N tested
1 PCS VEXTA stepper driver CSD5814N-P tested
1 product rating- C173376 Lot 4 Vexta PK266-01B 2-Phase 1.8°/Step Stepping Motor (DC1A, 7.4Ω)
1 product rating- GATES 3VX400 SUPER HC VEXTA POWERBAND BELT
1 product rating- ONE USED VEXTA PH265M-31
1 product rating- ONE Vexta 2-Phase Stepping Motor Model PK264-02A
1 product rating- Oriental Motor ASD18A-K Vexta AlphaStep Closed Loop Motor Driver
1 product rating- Oriental Motor ASD18A-K Vexta AlphaStep series Closed Loop Motor Driver
1 product rating- ORIENTAL MOTOR PH265M-31 / PH265M31 (USED TESTED CLEANED)
1 product rating- Oriental Motor PK264-02A Vexta Stepping Motor 2-Phase 2Amp 1.4Ω PK26402A
1 product rating- ORIENTAL MOTOR PK545-NB / PK545NB (USED TESTED CLEANED)
1 product rating- ORIENTAL MOTOR UDX5114N / UDX5114N (REPAIR EVALUATION ONLY)
1 product rating- ORIENTAL MOTOR VEXTA PK266-01B STEPPING MOTOR UNIPOLAR 2 PHASE
1 product rating- ORIENTAL VEXTA STEPPING MOTOR UNIT PK264-02A 2- PHASE DC 2A 1.8/STEP
1 product rating- Vexta (Oriental Motor Co.), Model PK266-01B, Stepping Motor, DC 1A, 7.4 Ohm
1 product rating- Vexta 2 Phase Stepping Motor - PH265M-31
1 product rating- Vexta 2 Phase Stepping Motor 1/8" Step PK266-01B
1 product rating- VEXTA 2phase Oriental stepper drive CSD2109-P
1 product rating- Vexta PH265M-31 2-Phase Stepping Motor, DC6V, 0.85A/Phase
1 product rating- VEXTA PH265M-31 Stepping Motor, 2 Phase 0.9 degrees Per Step 6 Volt DC
1 product rating- Vexta PK244PA 2-Phase Stepping Motor DC 1.2A
1 product rating- VEXTA PK266-01B Stepping Motor 2-Phase 1.8o/Step 1ADC 7.4Ohm PK266-01B *NEW*
1 product rating- Vexta Stepping Motor PK266-01B w/USDigital E3-2500-250-I-D-D-B Encoder
1 x Vexta PH266-02 2 Phase Stepping Stepper Motor 1.8 deg/step DC 6v  1.2 AMP
1 x Vexta PH266-02 2 Phase Stepping Stepper Motor 1.8 deg/step DC 6v 1.2 AMP
1.0 out of 5 stars.
182698 New-No Box, Oriental K0177-M Vexta Brushless DC Motor 60W, 2000r/min
193316 New-No Box, Vexta A5246-9412K Stepper Motor, 2 Phase, 2.1A
1Pair New VEXTA EIC4081 EIC4091 ZIP-15  #F4594 CY
1Pair New VEXTA EIC4081 EIC4091 ZIP-15 #F4594 CY
1Pair New VEXTA EIC4081 EIC4091 ZIP-15 #F4594 CY 
1PC   used Vexta 2-Phase Driver UDK2120 Tested
1PC  USED VEXTA MSP101 Driver
1pc  Used VEXTA MSP101 Driver Tested
1PC  Used VEXTA Oriental motor speed regulator SG8030J
1PC  Used VEXTA Oriental motor stepping PK566-NB
1PC NEW VEXTA  SBR11-ZP
1PC NEW vexta  SS22M-SSSD
1pc NEW VEXTA governor DSP501M
1PC NEW VEXTA SBR11-ZP
1PC NEW vexta SS22M-SSSD
1pc Omron Proximity Switch TL-N5ME2 10-30VDC 2M
1pc USED    VEXTA drives MSP101        #TT2
1pc used  VEXTA  CSD2112-P
1PC USED  VEXTA 2phase Oriental stepper drive CSD2109-P
1PC USED Eastern VEXTA drive CSD2112-P
1pc USED FOR VEXTA STEP MOTOR PK545-NBC-C25 ,Without wire #T86m YS
1PC Used Good VEXTA ASD13C-A #T94R YS yh
1PC Used Japan Eastern VEXTA 28 Series 1.8 degree 0.95A Double Out Axis #w2916wx
1pc USED Oriental Motor Super Vexta UDX5107N 5-Phase Stepping Motor Amplifier
1PC Used Oriental VEXTA five phase stepper drivers plate PMD03C tested
1pc USED Super Vexta 5-Phase Motor Driver Model UDX5107 Tested Good
1pc USED Super VEXTA UDX5114 5-PHASE Servo Driver Tested
1pc USED Super VEXTA UDX5114 5-PHASE Servo Driver Tested
1PC used Vexta 2-Phase Driver UDK2120 Tested
1PC USED VEXTA 2phase Oriental stepper drive CSD2109-P
1PC Used Vexta 2-Phase Stepping Motor Model PK264-02A Tested
1pc USED Vexta 5 phase Stepping Driver Motor DFC1507 Tested with Warranty
1PC USED VEXTA AXHD30K 24VDC Motor Driver Tested Good
1Pc Used Vexta AXUD40C ms
1PC Used VEXTA AXUD40C tested
1pc used VEXTA C7325-9012
1PC USED VEXTA CSD2109-P Oriental 2-phase Stepper Driver Tested Good 24-36V 1.4A
1pc used VEXTA CSD2112-P
1PC USED VEXTA CSD2120-P Oriental Stepper Motor Driver (CSD2120P) 2.8A Good
1PC Used VEXTA CSD5814N-P Oriental Stepper Driver (CSD5814NP)
1pc used VEXTA drive AXHD30K
1pc used VEXTA drive CSD5714B
1PC Used VEXTA drive MSP-1W
1PC Used VEXTA Driver ASD18B-K
1pc USED VEXTA drives MSP101 #TT2
1pc USED VEXTA drives MSP-2W
1pc USED VEXTA drives MSP-2W
1PC used Vexta Electric machinery 0GN60K
1PC used Vexta Electric machinery 0GN60K
1PC USED VEXTA MC-S0514-L
1PC USED VEXTA MC-S0514-L
1PC Used VEXTA Motor PK243-01B tested
1PC used VEXTA Motor PK566-NB  #fi
1PC used VEXTA Motor PK566-NB #fi
1PC USED VEXTA MSP101 Driver
1PC used VEXTA MSP101 Driver Tested
1PC used VEXTA MSP101 Driver Tested Free Shipping
1PC used Vexta MSP301N Speed Controller
1PC used Vexta MSP301N Speed Controller
1PC Used VEXTA Oriental drive CSD2112-P
1PC Used Vexta Oriental Motor 5 Phase Driver CSD5814N-P
1PC USED Vexta Oriental Motor CSD5814N-P  Drive card
1PC USED Vexta Oriental Motor CSD5814N-P Drive card
1PC used VEXTA Oriental Motor Drives ASD13C-A Tested
1PC used VEXTA Oriental Motor Drives ASD13C-A Tested
1PC Used Vexta Oriental Motor PK564AN-TG10 Stepping Motor Tested
1PC Used VEXTA Oriental motor speed regulator SG8030J
1PC Used VEXTA Oriental motor stepping PK566-NB
1PC USED Vexta Oriental Motor UDK5107N
1PC USED Vexta Oriental Motor UDK5107N
1PC USED VEXTA ORIENTAL SG8030J
1PC used VEXTA ORIENTAL SG8030J #fl
1PC USED VEXTA Oriental stepper drives MSP-2W
1PC Used Vexta Oriental Stepping Motor PK566-NA
1PC USED VEXTA PH265M-31
1PC Used VEXTA PH265M-31 tested
1PC Used VEXTA PK266-03A
1PC USED VEXTA PK545-NA-C21 5-phase Stepping Motor Tested
1PC USED VEXTA PK566AW Stepping Motor #T85M YS
1PC Used VEXTA Servo Driver RKD514L-C
1PC USED VEXTA SG8030J 24V #P2389 YL
1PC USED VEXTA stepper driver CMD2109P board type
1PC Used VEXTA Stepper Driver DFC5107P Tested Good Condition
1PC Used VEXTA Stepper Driver DFC5107P Tested Good Condition
1PC used VEXTA Stepper Driver PMD07U
1PC USED VEXTA Stepping driver CSD2112-P
1PC USED VEXTA Stepping driver CSD2112-P fast ship#XR
1PC USED VEXTA stepping driver PMD07U
1PC Used VEXTA Stepping motor motor PK266-03A
1Pc Used Vexta TMP-1 ic
1pc used VEXTA UDK5107N   #TT2
1pc used VEXTA UDK5107N #TT2
1PC used VEXTA UDX5114   #1
1PC used VEXTA UDX5114 #1
1pc VEXTA  5 phase stepper driver UDX5107N supporting PH569-A 10 lines  #F334 CY
1Pc Vexta 2IJ3GB-A Used nc
1PC VEXTA 2phase Oriental stepper drive CSD