2.0以前的WINCE也是一个让人发狂的软件,不光可靠差,实时也相当差劲,让人怀疑这玩意只能用来做做显示屏,后来wince2.0出来后还好一点,但个人对WINCE还是有抵触,可能是当初吃苦头吃多了,总认为一个工控产品不适合选用WINCE做操作系统,因为WINCE的系统结构包括兼容、开放、图形方面的优点都是针对手持消费类产品的,如PDA之类,对于工控需要的高实时和高可靠实在有点不及格。这一方面linux要更差一些,因为linux是为商用电脑开发的,很多公司都在为linux进行减肥并把抢占式的调度机制强行加入linux,从而可以使linux可以用在嵌入式的环境,但WINCE有的缺点它也都有,同时还要更严重,所以也不是一个好的选择。在操作系统方面,其实像VXWORKS和NECLUES之类的可能是一个不错的选择,因为用户多是工业方面的,对系统的可控制比较强,如果是高要求的开发者还可以买源码,这样如果操作系统内有问题就可以自己调试,我们就曾发现NECLUES操作系统的8019驱动方面有问题,主要是实时高速通信会有堵塞的问题,后来发现这一部分代码是从linux的源码中移植过来的,所以linux也有类似的问题。
对于PC_BASE体系更要命的是低档X86的配套芯片都已停产,包括DRAM等,使大家想接着使用386、486、586都不可能了,(我一直很喜欢ICOP的M6117,可惜现在DRAM真是买不到新货,全吃库存了),除非使用旧芯片。同时现在intel和微软已完全放弃了向下兼容的规则,使PC_BASE存在的意义日益减少。没有哪家工控厂商都跟上这两位大佬的更新速度,当你的产品准备面市时,你会发现你使用的所有器件均已停产,你只能上二手市场去买拆机件。
在PC_BASE发展过程中大多数厂商都遇到了PC_BASE单体成本高、需要用户有较强的开发能力的问题,使PC_BASE的量很难做大,对厂商的技术支持的能力和要求很高。为此很多工控机的厂商都找到了像KW、infoteam、ISAGRAF、3S这样的软逻辑开发商,利用工控机或者PC104+IO板卡来组成一个控制平台,这种控制平台大的优点在于可以支持现有PC的各种资源,使监、控可以做在一体,缺点主要是从小型PLC来说,成本太高,从中大型PLC来说点数又太少,同时抗干扰和抗振动方面存在许多架构问题。
在前些年我们花了很多的时间试用过多种不同类型的中想选一款理想的处理器而不可得,那个时侯民品方面的工程师都将目光转向ARM,因为大多数情况下在WINCE和linux上开发X86的软硬件和在ARM上开发类似的程序难度差别不大,而且ARM的成本比X86要低很多。我们试用了几种ARM后(当时ADI公司的工业级ARM还没出来)感觉ARM用在工业上面不大理想,大把显示、音频、VGA、以太网MAC之类的功能都在工控常规平台内用不上,而且ARM的抗电磁兼容方面也是一个头痛的问题,对于一般要求的2000V快速脉冲还可以满足,但再向上走就很难做到。目前来说选择可能会简单很多,相当多的工业用ARM、coolfire、AVR、M16使开发者有更多的选择,其中做为控制来说,M16真是一个很合适的处理器,可惜是产的。
1.4、PLC、DCS、PC的交叉点:
Juniper PB-1GE-SX-B
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JUNIPER P-4CHDS3-QPP 750-005635 $500
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Juniper STM-16/OC-48 Sonet SMF IR PIC module 710-001283
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Juniper STM-16/OC-48 Sonet SMF IR PIC module 710-001283
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Juniper STM-16/OC-48 Sonet SMF IR PIC module 710-001283
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Juniper STM-16/OC-48 Sonet SMF IR PIC / module
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Juniper STM-16/OC-48 Sonet SMF IR PIC / module
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Juniper MCS Miscellaneous Control System 750-001226
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Juniper Sonet/SDH OC-192/STM-64 SR-2 PIC 750-003184
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M160-FPC2-E JUNIPER M160 ENHANCED FLEX PIC IPC5DG0BAA
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Juniper M160-FPC2-E High Bandwith Flexible PIC Module
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Juniper Netscreen SA1000 SA 1000 Security Appliance GF
Juniper ES2-SRP-IOA Module
Juniper P-1OC12-SON-SMIR
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Juniper J4300 J4300BASE-AC Router Junos 8.0 R1.9
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Juniper SSG-5-SB-W-US SSG 5 Wireless Gateway Firewall
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Juniper PB-4DS3-ATM M160 4PT ATM DS3 PIC, PB4DS3ATM 750
Juniper PB-1OC12-ATM-SMIR for M160/M40e
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JUNIPER PB-1OC12-SON-SMIR STM-4/OC-12 SMF-IR M160
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Juniper M20 RE-333-768 Routing Engine Card (just RE)
Juniper M20 SSB-E-M20 Card (card only) Internet Proc II
JUNIPER * 710-001889 * 4-PORT FAST ETHERNET PIC MODULE
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Juniper Netscreen SSG-5-SH Secure In Juniper Box 256MB
Juniper I-1OC48-SON-SMSR, AF3340 1-PORT SONET/SDH
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Juniper Dual-port Channelized T1/E1 PIM for J-Series
JUNIPER NETWORKS P-1OC12-ATM-SMIR SONET/SDH PIC REFURB
ERX-4T3ATM-IOA JUNIPER DS3 ATM I/O IOA
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Juniper PB-1GE-SX-B module **1 Year Warranty**
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JUNIPER CT3-3 and CT3/T3-3I/O ERX Set w/ 1Yr Warranty
Juniper Networks Peribit SM-500 WAN Accelerator WARRANT
UNIQUE ART STAND ”PEDISTAL” JUNIPER WOOD 37 1/2 X24
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Juniper / Netscreen 5GT NS-5GT-101 Firewall / VPN Appli
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Juniper PB-4E3-ATM 4-Port ATM E3 PIC for M160 Router
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Unisphere Juniper ERX1400 SRP-10-ECC 10-Gbps SRP module
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JUNIPER NETWORKS NETSCREEN NS-025-001 FIREWALL VPN NEW
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Juniper P-1OC12-ATM-SMIR P1OC12ATMSMIR
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Juniper NS-IDP-50 Intrusion Detection & Prevention App
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Juniper PB-1OC12-ATM-SMIR 1Port ATM OC-12/STM4 PIC M320
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Juniper PB-1OC48-SON-SMSR OC48 M160 M40e M320
Juniper P-1OC12-ATM-SMIR 1 Port STM-4/OC-12 ATM M20/M40
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Juniper P-1OC12-SON-SMIR PIC STM-4/OC-12 SONET M20/M40
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Juniper M160 Router M160-FPC2-E Enhanced FPC
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Unisphere ( Juniper ) ERX 1400 Base 14 Chassis
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Juniper P-1OC12-SON-MM PIC 1-Port SONET/SDH OC12 MM
1-port SONET/SDH OC-12/STM4 PIC, Multimode
Juniper P-1OC12-ATM-SMIR 1-Port ATM
Juniper Netscreen 204 Firewall NS-204-007 / NS-204-001
ECoptical – EX-SFP-10GE-SR – For Juniper – NIB
JUNIPER NETWORKS SFM-M160-S W/ INET PROCR IPC3ZX0
JUNIPER PB-1OC12-ATM-SMIR STM-4/OC-12 ATM SMF-IR
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Juniper P-1GE-SX Module M20 M40 GF
Juniper P-TUNNEL TUNNEL PIC M20 M40