进入90年代后期，由于用户对开放性的强烈要求和压力，由于信息技术的大力推动，PLC如果还停留在原有的专用而又封闭的系统概念上，它将坐以待毙。于是PLC进入了其发展的第四阶段。其特征是：
在保留PLC功能的前提下，采用面向现场总线网络的体系结构，采用开放的通信接口，如以太网、高速串口等。
采用各种相关的国际工业标准和一系列的事实上的标准。
值得注意的是PLC和DCS这些原来处于不同硬件平台的系统，正随着计算技术、通信技术和编程技术的发展，趋向于建立同一硬件平台，运用同一个操作系统、同一个编程系统，执行不同的DCS和PLC功能。这就是真正意义上的EIC三电一体化。或者说DCS和PLC的形态将会变化，而它们的功能依然存在。其中的关键技术应该是嵌入式PC系统及支持现场总线的I/O（硬件），以及以IEC 61161-3为基础的编程系统及强实时(hard real-time)操作系统。
PLC在中国的发展
Siemens SBH 800 SBH2008 SBH2008DV 800A Amp SB08TP02G
Square D Altistart 46 ATS46C48N Soft Start 350 HP ATS46
Vooner VaneGard Vacuum Pump VG 7 VG7 Basic-M VG7B-M
Sew Eurodrive RF93DT10 5HP Ratio:60.96 Gear Reducer REM
Omron NT610C-DT151-V2 Interactive Display NT610CDT151V2
Milroyal Milton Roy pump Model MB1-M42-H562 2 HP motor
Milroyal Milton Roy pump Model MBH12B56B2M 2 HP motor
ABB Megamax SACE F1S F1 F1S1250 1250 Amp 690V Breaker
Westinghouse 350 HP 1765 RPM Induction DP Motor 5009-S
Siemens RL-2000 RL 2000 Amp Static Trip III RMS LSIG
Westinghouse Drawout Frame SPB 100 65 16SPBDOS 1600 A
GE Power Break PowerBreak TPSS6620G 2000 Amp 2000A A
Cutler Hammer Westinghouse NDC NDC3800T32W 800 Amp A
Telemecanique 5600 Motor Control Center 600 Amp NEW
Siemens SBS 2000 SBS2020 SBS2020F 2000Amp Amp SB20TLSIG
GE Spectra Series ADS36800LB Bus Plug 800 Amp Fusible
Cutler Hammer Breaker ND312T32W 1200 Amp A 1200A
Omron NT610C-DT151-V1 Interactive Display NT610CDT151V1
Westinghouse SPCB 2000 Amp SPCB2000 2000A Trip LSIG
Westinghouse Seltronic HNC31200F 1200 Amp A 1200Amp
Westinghouse DS-632 DS632 3200 Amp Amptector I-A LSIG
Westinghouse DS-632 DS632 3200 Amp Amptector IA LSIG
Westinghouse DS-632 DS632 3200Amp Amptector I – A LSIG
Westinghouse DS-632 DS632 3200A Amptector I – A LSIG
Westinghouse DS-632 DS632 3200 A Amp Amptector I-A LSIG
GE AKR-6D-30H 800 A Amp Air Breaker Versa Trip LSG 635V
Klockner-Moeller NZM12-1250 with Trip ZM12-1200 A Amp
GE AKR-6D-50 1600 A Amp Air Breaker MVT Trip LSG 635 V
Cutler-Hammer Power Breaker DSL II 620 DSLII 2000A Amp
Westinghouse Seltronic HNC31200F 1000 Amp A 1000Amp
Cutler-Hammer Power Breaker DSL II DSLII-620 2000 Amp
Westinghouse SPCB 2000 Amp SPCB2000 2000A Trip LIG
Cutler-Hammer Power Breaker DSL II 620 DSLII 2000 Amp
Westinghouse DS-632 DS632 3200 Amp A Amptector IA LSIG
Westinghouse Solid State Starter Soft ES360 360 Amp ES
C-H CH Westinghouse HND3800T107W Optim 800 Amp 800A A
Eaton Cutler Hammer SVX040A2-4A1N1 40 HP VS Drive NIB
Omron IDM Controls P5+ Series CIMR-P5U4055 VT5 100 HP
GE AKR-6D-30H 800 A Amp Air Breaker Versa Trip LSG 635V
GE AKR-6D-30H 800 A Amp Air Breaker Versa Trip LSG 635V
Siemens Sensitrip III Breaker SCLD69600 600A A 600 Amp
Sew Eurodrive K86DT9 2 HP Ratio:107.31 Gear Reducer NEW
Sew Eurodrive FAF67 1.8HP Ratio:162.31 Gear Reducer NEW
Eaton Cutler Hammer 600 Amp Bus Fusible Switch P3F366R
Zenith 800 A Amp ZTS81EC-31 Transfer Switch 208 V 3 PH
Sew Eurodrive DFT100 5 HP K96 460V Gear Reducer Box NEW
ABB Type K800 S K800S 800 Amp 800A Air Breaker LI
Eaton Cutler Hammer SVX040A2-4A1N1 40 HP VS Drive NIB
Square D NHL361200 NHL 1200 Amp A 1200A High Interrupt
Telemecanique LC1-FX43 Vacuum Contactor 1600A LC1FX43
Westinghouse DS-632 DS632 3200 Amp Amptector I – A LSG
Telemecanique Altivar 66 ATV66D79N4 AC Drive 75HP/100HP
Eaton Cutler Hammer SVX040A2-4A1N1 40 HP VS Drive NNB
Reliance Electric Induction AC Servo VZ3000 UVZ3202 OPC
GE High IC TKL12S 1000 Amp 1000A A RMS9 TS20LSIGT2 1000
GE High IC TKL12S 800 Amp 800A A RMS-9 TS20LSIGT2 800
Monitek / Sentex Turbidimeter TT6 210 211 sensor NIB
Siemens Sentron SCMD69800ANGT SCMD69800 Amp 800A A M/N
Square D Schneider Masterpact NW16H1 1600 Amp 800A LSIG
Toshiba E3 VT130E3U410K 100HP Inverter VS Drive 100 HP
Benshaw RSi-075-H-4-L 100 HP Variable Speed Drive 125A
Sew Eurodrive K76DT90 2HP Ratio:108.51 Gear Reducer NEW
GE AKR-6D-50 1600 A Amp Air Breaker MVT Trip LSIG 635 V
Square D PowerPact I Line PJA36120 U44A 1200Amp 1200 A
Indramat MDD112D-N-030-N2M-130PB2 Magnet Servo Motor
GE Power Break PowerBreak TPS203F 2000 Amp 2000A A
Reliance Electric RE 20V2160 GV3000 VS Drive 20 HP NIB
Siemens K-1600 K1600 1600Amp Static Trip III draw-out
GE General Electric SK SKPB36BC1200 1200 A 1200Amp
Square D I Line ME ME36600LIG ME36600 800 Amp Frame
RP Adams Automatic Water Strainer VWS 150 PSI 3080 GPM
Fanuc A06B-0147-B177 AC Servo Motor A22/2000 3.8 kW 3PH
Square D I-Line NC361200 NC-361200 NA 1200 Amp 1200A A
Westinghouse SPCB 2000 Amp SPCB2000 1000A Trip LSG
Reliance Electric Induction AC Servo VZ3000 UVZ3202 14A
Westinghouse DS-632 DS632 3200 Amp Satin etc. 21 LS
GE AKR-6D-50 1600 A Amp Air Breaker MVT Trip LI 635 V
Westinghouse DS-632 DS632 3200 Amp Amptector I – A LSI
Saftronics GP10 Vector AC Drive GP10E9ST34040B1 40 HP
Square D PowerPact I Line PJA36080 CU44A 800Amp 800 A
Cutler Hammer Breaker ND312T32W 1200 Amp A 1200A 600A
C-H CH Westinghouse HND3800T107W Optim 800 Amp 800A A
C-H CH Westinghouse HND3800T107W Optim 800 Amp 800A A
Square D I-Line LX LXI36500 I-Limiter 500 Amp 500A A
Eaton Cutler Hammer 400 Amp Fusible Switch P3F365RN NEW
Klockner-Moeller NZM12-800 with Trip ZM12a-70-NA Amp
Toshiba Houston TEFC Motor 200 HP 1770 RPM Fr. 447TZ
Siemens-Allis LA-3000A Air Circuit Breaker Draw Out
ITE Siemens Breaker HRXD63B200 2000 Amps A 2000Amp
Cutler Hammer 1200 Amp 1200A A HND312T32W A12NES1200T1
Federal Pacific 220 kVA 460 / 460Y / 266 3PH Y 220kVA
Reliance Electric 2GU41075 75HP GP2000 VS Drive 75 HP
Square D I-Line Main Breaker Panelboard 225 Amp 600 V
Federal Pacific 220 kVA 460 / 460Y / 266 3PH Y 220kVA
ITE Siemens Breaker CP3 L160 CP3L160 ET 1600 Amp Trip
Allis-Chalmers LA-3000A Air Circuit Breaker Draw Out
Square D I-Line NX NX361200 800 Amp A 800A LSI
CH Westinghouse HND 800 Amp 800A A HND3800T32W 8NES800T
Westinghouse SPB 100 Pow-R Breaker SPB100 1600 Amp A
Sew Eurodrive K76SDT 1 HP Ratio:118.45 Gear Reducer NEW
Sew Eurodrive KA76SDT 1 HP Ratio:118.4 Gear Reducer NEW
Westinghouse WH A200M5CAC Size 5 Starter 2045A41G01 NIB
Sew Eurodrive DFT80K4 3/4HP K96R62 Gear Reducer Box REM
Square D Schneider Masterpact NW12HF 1200 Amp 1200A A
CH Westinghouse 1200 Amp 1200A A HND312T32W 12NES1200T
Yokogawa MP31 CPU MP31-1N MP311N H70909047 PLC
Westinghouse FSP Interrupter Switch 1200 Amp 1200A 15kV
Acme Transformer 225 kVA 480/240/120 3 PH 225kVA Delta
Square D Mod Model 4 Sz Size 6 MCC Bucket 8536SHO2 MCCB
Louis Allis AC Motor 150 HP 1780 RPM 444T 575V
Allis-Chalmers LA-3000 3000 Amp A Air Circuit Breaker
Square D I-Line LX LXI36400 I-Limiter 400 Amp 400A A
ABB 1600 Amp Type LKE-16 LKE16 MPS-5 MPS5 Air Breaker
Dynamatic Eddy Curr. Clutch AT-441000-4041 90 DC 100HP
Reliance Electric WR-D4004 PSC 4000 Series WRD4004 CPU
