计算机控制系统也是经历了集中控制、分层控制、基于现场总线的网络控制等几个发展阶段，它们的发展过程是非常相似的。
随着企业信息网络的深入应用与日臻完善，现场控制信息进入信息网络实现实时监控是必然的趋势。为提高企业的社会效益和经济效益，许多企业都在尽力建立全方位的管理信息系统，它必须包括生产现场的实时数据信息，以确保实时掌握生产过程的运行状态，使企业管理决策科学化，达到生产、经营、管理的化状态。信息一控制一体化将为实现企业综合自动化CIPA（computerintegratedplantautomation）和企业信息化创造有利条件。
企业信息网络与控制系统在体系结构发展过程上的相似性不是偶然的。在计算机控制系统的发展过程中，每一种结构的控制系统的出现总是滞后于相应计算机技术的发展。实际上，大多数情况下，正是在计算机领域一种新技术出现以后，人们才开始研究如何将这种新技术应用于控制领域。鉴于两种应用环境的差异，其中的技术细节作了适当修改和补充，但关键技术的原理及实现上，它们有许多共同的地方。正是由于二者在发展过程中的这种关系，使得实现信息一控制一体化成为可能。
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,-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