計算機控制系統(tǒng)也是經歷了集中控制、分層控制、基于現場總線的網絡控制等幾個發(fā)展階段，它們的發(fā)展過程是非常相似的。

隨著企業(yè)信息網絡的深入應用與日臻完善，現場控制信息進入信息網絡實現實時監(jiān)控是必然的趨勢。為提高企業(yè)的社會效益和經濟效益，許多企業(yè)都在盡力建立的管理信息系統(tǒng)，它必須包括生產現場的實時數據信息，以確保實時掌握生產過程的運行狀態(tài)，使企業(yè)管理決策科學化，達到生產、經營、管理的化狀態(tài)。信息一控制一體化將為實現企業(yè)綜合自動化CIPA（computerintegratedplantautomation）和企業(yè)信息化創(chuàng)造有利條件。

企業(yè)信息網絡與控制系統(tǒng)在體系結構發(fā)展過程上的相似性不是偶然的。在計算機控制系統(tǒng)的發(fā)展過程中，每一種結構的控制系統(tǒng)的出現總是滯后于相應計算機技術的發(fā)展。實際上，大多數情況下，正是在計算機領域一種新技術出現以后，人們才開始研究如何將這種新技術應用于控制領域。鑒于兩種應用環(huán)境的差異，其中的技術細節(jié)作了適當修改和補充，但關鍵技術的原理及實現上，它們有許多共同的地方。正是由于二者在發(fā)展過程中的這種關系，使得實現信息一控制一體化成為可能。

SQUARE D TRANSFORMER CAT#EE75T3HF 75KVA HV: 480V LV: 208Y/120 3 PHASE

Square D Transformer Disconnect # 9070SK3000A2D1 " "

SQUARE D TRANSIENT VOLTAGE SURGE SUPPRESSOR CAT# TVS1EMA16A 160kA 120/240V

SQUARE D TRANSIENT VOLTAGE SURGE SUPPRESSOR CAT#TVS1EMA24A 240kA 120/240V NIB

Square D Triple 800 Amp MCCB Thermal-Magnetic 800Amp i-Line Breaker Main Switch

Square D TVS1EMA12S Transient Voltage Surge Suppressor

Square D TVS2EBA12A Transient Voltage Surge Suppressor

Square D TVS2EMA12A Transient Voltage Surge Suppressor

SQUARE D TVS2EMA12AIC Transient Voltage Surge Suppressor 208Y/120V 3 Ph 4 wire

SQUARE D TVS-2EMA12AISWT NSFP TVS2EMA12AISWT

SQUARE D TVS-2EMA24AIC NSFP TVS2EMA24AIC

SQUARE D TVS4EBA24A NSFP TVS4EBA24A

Square D TVS4EMA16AI 160 KA Peak Surge Protective Device (CIR1749)

SQUARE D TVS4EMA24AC 277/480 TVSS (U) SURGE SUPPRESSOR

Square D Type JGA36250 Circuit Breaker 3 Pole

Square D Type KA26250AC Circuit Breaker 2 Pole

Square D Type MEL436LSGZ1 Circuit Breaker no plug

Square D Type PBTB502G Buss DuctTap 225 Amp

SQUARE D TYPE PE 1600 AMP GROUND FAULT CIRCUIT BREAKER.............ZF-301

Square D Type QE3150VH Plug in Main Breaker

Square D type QMB 3P 400A 600V Single Saflex Series E1

Square D type QMB-3640 3P 400A 600V

Square D type QMB366MW 600A 3-Pole 600V Series 1

Square D Type VR Ground and Test Device - Excellent

SQUARE D V5D3122Y000 4.76KV 1200A DO EO MEDIUM VOLTAGE CIRCUIT BREAKER

Square D V5D7133Y000A 1200A 15kV Vacuum Breaker 1200 A Amp 15 kV Type VR

Square D V5D7233Y000A 2000A 15kV Vacuum Breaker 2000 A Amp 15 kV Type VR

Square D VACARC AC High Voltage Vacuum Circuit Breaker - 4.76KV - 1200Amp

Square D VACARC AC High Voltage Vacuum Circuit Breaker - 4.76KV - 1200Amp

Square D Var-Gard Automatic Power Factor Control - 300KVAR - 480Volt - 600Amp

Square D Var-Gard Automatic Power Factor Control Equipment - 250KVAR 480Volt 3W

SQUARE D VR V5D4133YJ00A 4.76KV 1200A DO EO MEDIUM VOLTAGE CIRCUIT BREAKER

SQUARE D VX5A66D466M2 FNFP VX5A66D466M2

SQUARE D WA4JJR43A9SFBXXCX 600 V 3200 AMP L I G INSULATED CASE CIRCUIT BREAKER

Square D WA8FFR64A3FFBFXXCA MasterPact Low-Voltage Power Circuit Breaker 2000A

Square D WATCHDOG 150 KVA Transformer 480 Delta 208Y/120 Volt ONE GUARANTEE

Square D XBT F024610_XBTF024610_XBT FO2461O_XBTFO2461O with Memory Module PV:02

Square D XBT F024610_XBTF024610_XBT FO2461O_XBTFO2461O with Memory Module PV:06

SQUARE D XBT-F011310 MAGELIS OPERATOR INTERFACE XBTF011310 REPAIRED

SQUARE D XBT-F024610 USPP XBTF024610

SQUARE D XBT-GTW450 NSPP XBTGTW450

SQUARE D XR-IA-DI NSFP XRIADI

SQUARE D XR-IA-DI NSPP XRIADI

Square D YA8KKR63B3LFBFWXCA MasterPact Circuit Breaker 635V 4000A 3P

Square D, NXP361000, 600V, 1000 Amp, Circuit Breaker

Square D, Omegapak, AC Drive, Class 8803, Type P00CO4N

SQUARE D,26039581-003,TYPE IPaCS,HEAVY DUTY TRANSFORMER

SQUARE D,DS BREAKER TEST KIT MODEL 2537-3 WESTINGHOUSE, CUTLER HAMMER AMPTECTOR

Square D,I Line Panelboard complete,1200A Main Lugs only, 86" for breakers,

Square D/Schneider Electric KI36175 600 Volt 3 Phase SEALED OFFERS ACCEPTED

Square D/Schneider Electric LX36125G Circuit Breaker SEALED OFFERS ACCEPTED

Square D/Schneider Electric MAP26800 800 Amp braker SEALED OFFERS ACCEPTED

Square D/Symax 8010 SFI510 Interface Board for PC, Series A1/Rev 2.01 (NIOP)

Square D/Symax 8030-CRM-232

Square D/Symax 8030-RIM-126

Square D/Symax 8030-SCP-424

Square D/Symax 8030-SCP-444

Square D/Symax/ 8020-SCP-423/8020SCP423/SCP-423/SCP423 OFFERS ACCEPTED

Square D: 10S9FIS Dry Transformer. 1PH, 10KVA, 208V

Square D8538SBW33V81ACFF4H30P42T1 Combination Motor Starter 30A 4/4X

Square D-HVL Load Current Interupter Switch HVL30503

SQUARE I-LINE II BUSWAY CAT# AP2525-G10 SER. 1. ALUM 1200A, 3PH, 4W W/ INT. GRND

SQUARE-D # LX36400-1380 LX36400 400 AMP I-LINE BREAKER

SQUARE-D # NX361000 CIRCUIT BREAKER

SQUARE-D # NX361200 I-LINE 1200 AMP W / ACCESSORIES

SQUARE-D (8903 SZ0-2) LI