P0903CW

在现场总线这一节的后面我谈一谈对工业以太网的看法，在这个盲目推崇以太网和TCP/IP协议的年代，我要对工业以太网泼冷水，在未来的工业系统中以太网的必要是无可以厚非的，但以太网不是的，它在实现与HMI、监视系统的联接方面有超人的优势，这是因为他可以很方便的提供跨区域跨平台的互操作和访问，特别是基于Web的e设备是未来的一个方向，这使广大厂商都在自己的系统里面上以太网上TCP/IP。这是没有错的，这个方向是相当正确的，但是越来越多的工程师和科技工作者希望用工业以太网一网打净所有需要现场总线的场合，这就不对了。工业以太网是一种商业的办公用网络，它在好多个领域是不适合的，

 

1、对时间要求高的系统（实时、重复、顺序）；

 

2、对效率要求比较高的系统；

 

3、对成本要求比较高的系统；

 

4、对可靠要求高的系统。

 

这是因为以太网和TCP/IP协议并不适合于工业的现场层面或者实时层面的通信，其抢占式的总线结构使时间的可靠得不到保证、多层次的封装导致效率的低下，对于的保贵机时浪费太多、开放过度导致的安全不够等。对于IP的反思在通信行业上已得到广泛的认同，原本想在3G的时代一定会是IP的天下，但实际的情况发现，在通信中的主干环节IP仍然因为效率低下而无法满足要求(很多国际大公司都在彻底IP的理想上面吃了苦头)，而不得不退回去仍使用ATM之类的精干协议。

 

 

Allen Bradley 1333-YAW 1.5KW AC Drive
Allen Bradley 1336-B050-EAG-LZ Allen Bradley 1336 75 Amp Inverter
Allen Bradley 1336-L4 Interface Board
Allen Bradley 1336-MOD-KB005 Allen Bradley Brake Unit
Allen Bradley 1336-MOD-KB010 Allen Bradley Brake Unit
Allen Bradley 1336-MOD-KB050 SER D Bulletin 1336 Dynamic Brake
Allen Bradley 1336-WB110 Bulletin 1336 Braking Chopper
Allen Bradley 1336E-BRF100-AA-EN Allen Bradley 1336 Impact 19kva 24A AC Drive
Allen Bradley 1336F-B020-AE-EN 1336 Plus 2 Sensorless Vector Drive. 27kva.
Allen Bradley 1336F-B025-AE-EN Allen Bradley 1336 Plus II Inverter 18KW
Allen Bradley 1336F-B030-AE-EN 1336 Plus 2 38kva Sensorless Vector Drive
Allen Bradley 1336F-B050-AE-EN 1336 Plus 2 Sensorless Vector Drive. 61kva
Allen Bradley 1336F-B075-AE-EN Allen Bradley 1336F 96Kva Sensorless Vector Drive
Allen Bradley 1336F-B125-AE-EN Allen Bradley 1336 PLUS 2 138KVa Inverter
Allen Bradley 1336F-B150-AE-EN Allen Bradley 1336 159KvA Inverter
Allen Bradley 1336F-BRF150-AE-EN 1336 Plus2 Sensorless Vector 15KW Inverter
Allen Bradley 1336F-BRF20-AE-EN Allen Bradley 1336 Sensorless Vector Drive.
Allen Bradley 1336F-BRF50-AE-EN Allen Bradley 1336Plus2 5.5Kw Inverter
Allen Bradley 1336F-BRF75-AE-EN Allen Bradley 1336 Inverter 5.5KW
Allen Bradley 1336F-BRF75-AE-FR Allen Bradley 7.5Kw Inverter
Allen Bradley 1336PLUS Allen Bradley 1336PLUS Inverter
Allen Bradley 1336S-B010-AE-EN Allen Bradley 1336 13Kva Inverter
Allen Bradley 1336S-B015-AA-DE Allen Bradley 1336 15Kw Inverter
Allen Bradley 1336S-B015-AA-EN Allen Bradley 1336 Plus Inverter 15KW
Allen Bradley 1336S-B020-AE-EN Allen Bradley 1336 Plus 20 Kw Inverter
Allen Bradley 1336S-B030-AE-DE-HA2-L5 Allen Bradley AC Drive
Allen Bradley 1336S-B030-AE-EN4 Allen Bradley 1336PLUS Inverter
Allen Bradley 1336S-B075-AN-EN 1336 75Kw Inverter
Allen Bradley 1336S-B125-A-EN Allen Bradley AC Drive 138kva 173A
Allen Bradley 1336S-BRF75-AE-FR4 1336 Plus Sensorless Vector AC Drive
Allen Bradley 1336VT-B030-EOR Allen Bradley Bulletin 1336VT 40 Amp Inverter
Allen Bradley 1388-AV60 Bulletin 1388 DC Servo Drive
Allen Bradley 1388B-AV40 Allen Bradley Bulletin 1388 20A DC Servo Drive
Allen Bradley 1389-AA09-A01 Allen Bradley 3.3Kw Servo Drive
Allen Bradley 1389-PAT10 Allen Bradley Bulletin 1389 Power Supply
Allen Bradley 1389-PAT10HR Allen Bradley Bulletin 1389 Power Supply
Allen Bradley 1391-AA15 Allen Bradley 1391 5.5Kw Servo Drive
Allen Bradley 1391-DES45-D1 Allen Bradley 1391 45A Axis Servo Drive
Allen Bradley 1391B-AA15 Allen Bradley Bulletin 1391 5.5Kw Servo Drive
Allen Bradley 1391B-AA45 Allen Bradley Bulletin1391 14KW Servo Drive
Allen Bradley 1394-AM03 Allen Bradley Bulletin 1394 2Kw AC Servo Drive
Allen Bradley 1394-AM04 Allen Bradley Bulletin 1394 3KW AC Servo Drive
Allen Bradley 1394-AM05 Allen Bradley Bulletin 1394 5Kw AC Servo Drive
Allen Bradley 1394-AM07 Allen Bradley 1394 AC Servo Controller
Allen Bradley 1394-SJT05-A Allen Bradley 1394 Digital Servo With Analog Contr
Allen Bradley 1394-SJT05-C-RL Digital Servo Controller (5kW Standard Version)
Allen Bradley 1394-SJT05-T Allen Bradley 1394 5Kw Servo Controller
Allen Bradley 1394-SJT05-T-RL Digital Servo Controller (5kW Turbo Version)
Allen Bradley 1394-SJT10-T-RL Allen Bradley 1394 Digital Servo Controller
Allen Bradley 1394C-AM03 Allen Bradley Bulletin 1394 2KW AC Servo Drive
Allen Bradley 1394C-AM50 Allen Bradley Bulletin 1394 10 KW AC Servo Drive
Allen Bradley 1394C-SJT05-D Allen Bradley Bulletin 1394 Digital Servo Control
Allen Bradley 1394C-SJT05-T Allen Bradley Bulletin 1394 Digital Servo Control
Allen Bradley 1395-A66N-C1-PZ Allen Bradley 1395 5.6Kw DC Drive
Allen Bradley 1397-B020N-FS2010-HA2-PE Allen Bradley 38 Amp 1397 DC Drive
Allen Bradley 1398-DDM-009 Allen Bradley Ultra Series Drive
Allen Bradley 1398-DDM-019 Allen Bradley Ultra Series Drive
Allen Bradley 1398-DDM-075 Allen Bradley Ultra Series Drive
Allen Bradley 1398-PDM-030 Allen Bradley Ultra Series Servo Drive
Allen Bradley 1398-PDM-150 Allen Bradley 65A AC Servo Drive
Allen Bradley 1404-M405A-ENT Allen Bradley Powermonitor 3000 Module
Allen Bradley 150-A135NBD SMCPLUS Soft Start
Allen Bradley 150-A15NBD Bulletin 150 Soft Start
Allen Bradley 150-A35NB SMC-2 Soft Start 22KW
Allen Bradley 150-A500NBD SMC Plus Soft Start Unit.
Allen Bradley 150-A54NBD SMCPLUS Soft Start
Allen Bradley 150-A68NB SMC2 37KW Soft Start
Allen Bradley 150-A97NBD Allen Bradley SMS Plus 55Kw Soft Start
Allen Bradley 150-B360NBD Allen Bradley Soft Start
Allen Bradley 150-D74NBD Allen Bradley SMC-Delta 74 Amp Soft Start
Allen Bradley 150-F135NBD Allen Bradley SMS-Flex Soft Start
Allen Bradley 160-BA01NPS1 Allen Bradley 0.37Kw Inverter
Allen Bradley 160-BA01NSF1P1 Allen Bradley 0.37Kw Inverter
Allen Bradley 160-BA02NPS1 Allen Bradley 160-DN2. 0.55KW AC Drive
Allen Bradley 160-BA04NSF1 Allen Bradley 1.5Kw Inverter
Allen Bradley 160-BA06NSF1 Allen Bradley 2.2Kw Inverter
Allen Bradley 160-BA10NPS1 Allen Bradley Inverter
Allen Bradley 160-BA10NSF1 Allen Bradley 3.73KW Inverter
Allen Bradley 160-BMB1 Dynamic Breaking Module