DCS的控制网络通常都是封闭的,通过一个历史数据库或者网关与外网交互,同时DCS对于工程师站、操作员站的定义比PLC工程体系要更为清晰和明显。
PLC:
小型微型PLC倒没什么冲突,因为结构和低成本的原因与其它两类产品完全不同。但中大型PLC因为大量使用PC_BASE技术使其与DCS和IPC+软逻辑基本上没有差别,只是因为这些厂商大多之前就是PLC厂商而且客户群都是PLC的客户,所以他的产品就叫PLC。
IPC+软逻辑:
在十几年前美欧的几个专家在这个问题有过一段很长时间的争论,围绕了一个问题是IPC+软逻辑如何实现才是合理的,因为当时主要有几种声音,一种是完全反对IPC在控制中的使用,因为显而易见的可靠性问题,包括操作系统的兼容性与可靠性如何并重。另一种是完全支持IPC在工控中的应用,并认为要使用标准的PC软硬件,这样才可以使兼容性和开放性的优点充分体现。后一种是一种折中的方案,把PLC插入IPC内,做为IPC的一个板卡。在实现上面也有这么几种方案:
方案一:标准操作系统,包括WINNT(含XP、2000、NT等)、linux、DOS,加软逻辑软件
TEKTRONIX TCP312 100 MHZ 30A DC CURRENT PROBE TCPA300
TEKTRONIX DG2020 DG 2020 DATA GENERATOR + MANUAL
Tektronix VX4353 Relay switch
Sony/Tektronix Oscope M/323- Spectrum Analyzer M/1401A
TEKTRONIX 528 1420 NTSC WAVEFORM MONITOR & VECTORSCOPE
Tektronix SD24 Dual-Channel TDR/Sampling Head, 20 GHz
Tektronix 496P 1kHz – 1.8GHz Spectrum Analyzer
Tektronix TSG271 PAL TV Generator
Tektronix TSG271 PAL TV Generator with 01
TEKTRONIX TDS684A DIGITAL OSCILLOSCOPE 1GHZ
TEKTRONIX TDS784A DIGITAL OSCILLOSCOPE 1GHZ
Tektronix 2465B 4 Channel Oscilloscope with Option 5
Tektronix TekRanger®2 TFS3031 Mini OTDR
Tektronix TekRanger®2 TFS3031 Mini OTDR
Enlarge
Tektronix VM700A Video Measurement Set VM 700A VM 700 A
Tektronix WVR611A SDI/COMPOSITE RASTERIZER
Tektronix 2247A 100 MHz Oscilloscope Counter/Timer
TEKTRONIX TLA7AA4 DS LOGIC ANALYZER 136CH 8MB DEPTH #2
TEKTRONIX MODEL TPG 20 DIGITAL PATTERN GENERATOR
TEKTRONIX TLA7AA4 DS LOGIC ANALYZER 136CH 8MB DEPTH #1
Tektronix TDS 460 4 Channel Digitizing Oscilloscope
Tektronix VX4334 4 Wire Reed Relay Scanner Master VXI
TEKTRONIX 11302 PROGRAMMABLE OSCILLOSCOPE W/PLUG INS!
@@@ CALIBRATED @@@ CALIBRATED @@@ CALIBRATED @@@
TEKTRONIX PG5110 50MHZ 2 CHANNELS PULSE GENERATOR OPT2!
Tektronix CTS710 SONET Test Set with 52/155/622 DS1/DS3
Tektronix ORR24 Sonet/SDH Optical Reference Receiver
Expedited shipping available
Tektronix TM515 w/ CG551AP, DC509, DM501A
Expedited shipping available
Tektronix Tempo TV220 CableScout TDR Fault Locator
Enlarge
TDS 360 TDS360 Digital Oscilloscope 200Mhz/ 1Gs/s
2465B Tektronix Scope opt 05, 1R, 10–no probes
Tektronix VX4236 6.5 Digital Multimeter VXI Module
Tektronix 496 Tek Spectrum Analyzer *Read Notes* Wrks
Tektronix TDS 320,2 Channel 100 MHz Digital Oscilloscop
Tektronix SD-24 Sampling Head (Reduced!)
THS720, THS 720, THS720A Oscilloscope 100Mhz/500Gs/s
TEKTRONIX 492 SPECTRUM ANALYZER OPT 1-2-3
Enlarge
Tektronix 7D15 255 MHz Universal Counter / Timer Plugin
One-day shipping available
TEKTRONIX 2236 OSCILLOSCOPE COUNTER TIMER MULTIMETER
Tektronix TDS430A Digitizing Oscilloscope, 400 MHz, 2ch
One-day shipping available
Tektronix 7104A Oscilloscope (2) 7A26, 7B53A, 7B85
Tektronix TDS 360 TDS360 digital scope, NIST-calibrated
additional free NIST recalibration within one year
Tektronix TDS 220 TDS220 oscilloscope, NIST-cal’d
additional free NIST recalibration within one year
Tektronix TSG130A NTSC Multiformat Generator
Tektronix 7L13 Spectrum Analyzer
Tektronix TDS350 Digital Oscilloscope, 200 MHz
TEKTRONIX 492 SPECTRUM ANALYZER OPT 1-2-3
Tektronix TekScope THS720P 100MHz Oscilloscope THS720
@CALIBRATED@SALE@100 MHz/ DIMM/ 500 MS/s@90DayWarranty@
Tektronix 1720SCH VECTORSCOPE , NTSC
Tektronix 2467 350 MHz 4-channel scope, NIST-certified
additional free NIST recalibration within one year
VX4730 Tektronix VXI 16 Bit D/A Converter, Rev: 1.4
TEKTRONIX 1710 1420 NTSC WAVEFORM MONITOR VECTORSCOPE
TEKTRONIX TDS 460A
SONY TEKTRONIX AFG2020 ARBITRARY FUNCTION GENERATOR
250MS/s synthesized FUNCTION GENERATOR WITH OPT 02
Tektronix SD24 Dual-Channel TDR/Sampling Head SD-24
TEKTRONIX 1750A
Tektronix P7313Differential Probe Accessory 020-2636-02
Tektronix P5210 High Voltage Differential HV Probe Test
Tektronix AG7 Audio Generator For the TG700 TEK-AG7 NEW
Tektronix AWG2005 4 Ch 20MHz Arbitrary Wave Generator
Tektronix 1755A Waveform/vector Monitor NTSC
TEKTRONIX AM503S CURRENT MEASUREMENT AM503A A6302 TM501