PLC產品發(fā)展至今從{dy}代的龐然大物，到今天的小型化、易于安裝，它在外形和體積等方面，發(fā)生了巨大變化。無論是從大到小，還是接口、外形的變化，都是為了讓用戶能快速、輕松的安裝、連接和啟動，為此各廠商都在尋求創(chuàng)新，以便讓它更易于操作和擴展，進而提{gx}率，降低人力和時間成本。
如今的PLC，運算速度、掃描速度、存儲容量、I/O點數，早已今非昔比。而在多CPU并行、指令的功能與數量、特殊功能單元、擴展能力等方面，也有長足的發(fā)展，如：順序控制、運動控制、過程控制等功能的集成，信息安全與設備診斷的理念等。
作為開放趨勢的重要因素之一，PLC的通訊一直為大家所熱烈討論。現場總線的發(fā)展，使得一個個獨立的PLC系統(tǒng)能夠相互連接，加之工業(yè)以太網與PLC的結合，PLC系統(tǒng)可方便接入信息化系統(tǒng)之中。為此，各種總線可謂百花齊放：ProfiBus/ProfiNet, CANOpen, DeviceNet,Ethernet/IP, POWERLINK，EtherCAT等。另外，GSM/CDMA/3G等無線網絡技術，也逐步應用。
如何連接外部系統(tǒng)和舊的系統(tǒng)？特殊傳感器如何連接？總線協(xié)議千變萬化，如何實現完全兼容？接口是否自診斷？編程接口是否統(tǒng)一？面對眾多來自實際應用的問題，您認為，PLC的通訊性能究竟應該怎樣發(fā)展？
從上個世紀九十年代開始，集成自動化的理念逐漸深入人心。在一個集成自動化體系里，系統(tǒng)中設備間能夠{zd0}程度上實現資源利用與共享。然而，集成自動化離不開強大的開發(fā)平臺的支持，開發(fā)工具不僅要支持PLC，還要解決故障診斷、網絡通信能力以及基本自動化硬件以外的附加高級語言軟件開發(fā)功能。
傳統(tǒng)的PLC生命周期，包括設備的選型、采購、設計、安裝調試、維護維修、服務等環(huán)節(jié)，而模塊化PLC，讓這些環(huán)節(jié)趨向標準和簡化。作為工程師的我們，工作于產品生命周期的各個環(huán)節(jié)，或設計、或采購、或調試、或維護，而在這些環(huán)節(jié)，您認為PLC會有怎樣的變革？
FUTABA MGT45-250 BALL GUIDE / BALL RETAINER WITH BASE
10 NEW PIECES!! NACHI 6203-ZZE BALL BEARING 17x40x12MM
NTN UCP-305JD1 PILLOW BLOCK MOUNTED BEARING 25MM (NEW IN ORIGINAL BOX)
LOT OF 2!! DAYTON 1L669 SHAFT COLLAR CLAMP STYLE 1-5/8" BORE?PILLOW BEARING
LOT OF 2!! TIMKEN 18337 CUP TAPERED ROLLER BALL BEARING OD 3.375" (NEW)
NSK 6311Z BALL BEARING 55X120X29MM (NEW)
LOT OF 2!! NSK 3212B?2ZRTNG ANGULAR CONTACT BALL BEARING
NEW!! TIMKEN 48685 W/ CONE 48620 CUP TAPERED ROLLER BEARING
FBJ 6315 ZZ BALL BEARING TWO SHIELDS 75x160x37MM (NIB)
LOT OF 6 BEARING!! SKF LBCR 16 LINEAR BALL BEARING 16x26x36MM
IKO NART15R BALL BEARING 15x35x19MM NEW?IN ORIGINAL BOX
LOT OF 2!! ZBF TY-63358-U2000-71 BALL ROLLER BEARING MG38-11?HI-CAP 40x108x30MM
LOT OF 8!! PEER FT-205-H BALL BEARING 2?BOLT FLANGE 62MM DIA.
SET OF 2 THK VR3 -150HX21Z CROSS ROLLER?GUIDE
LOT OF 4!! IKO CF10VBUUR CAM FOLLOWER BEARING M10x1.25 SHAFT
5 NEW PIECES!! SMR63?BEARINGS 3MM x 6MM?x 2MM
YHK P209 PILLOW BLOCK BEARING UNIT 45 MM
FSQ SN311 BEARING HOUSING UNIT 65mm / 2.5590
LOT OF 4!! IKO CF-12UU CAM FOLLOWER ROLLER BEARING 12x30x14MM (NEW)
ASK LCF-25AVUU LINEAR CASE FLANGE 25MM BUSHING BEARING
2 PIECES!! MICRO RW118-3 CROSSED BEARING?SLIDES 3-1/4" 80MM?LINEAR GUIDE RAIL
INTELLIGENT ACTUATOR?THK 03WX-60-200 LINEAR MOTION CONTROL LONG SLIDER 200MM
LOT OF 3! CONSOLIDATED F699-ZZ BALL BEARING 9 x 20 x 6 mm (NEW ORIGINAL BOX)
BANDO TL1008 TAPER LOCK BUSHING 5/8" BORE (3 NEW PIECES)
NEW!! GRAPHITE BUSHING WITH STEEL FIXTURE CYLINDRICAL GUIDE
NTN 30316-U TAPER ROLLER BEARING 80x170x42.5MM
2 PIECES! KBC UCFL206 FLANGED MOUNTED BEARING 30MM (NEW)
2 NEW PIECES!! INA 6208-C3 BALL BEARINGS40 x 80 x 18MM
NTN 318 Z BALL BEARING 90 x 190 x 43MM
2 NEW PIECES!! INA 6003 2RS SINGLE ROW BALL BEARING 17MM x 35MM x 10MM
NEW!! IKO BSR 1540-SL PRECISION BALL SLIDE 40x15mm
NSK 3311B 2ZRTNG ANGULAR CONTACT BALL BEARING
2 NEW PIECES!! FYH UCP 305 PILLOW BLOCKMOUNTED BEARING 25MM
LOT OF 3!! RBC SJ-7194-RS HEAVY DUTY NEEDLE ROLLER BEARING 1" DIA. SJ719RS
NEW!! STEYR 6210-K SINGLE ROW BALL BEARING 50MM x 90MM x 20MM
LOT OF 2!! FYH UCFL205 FLANGED MOUNTED BEARING 25MM (NEW IN?ORIGINAL BOX)
LOT OF 4!! PEER FHSFT-208-24G BALL BEARING 2 BOLT FLANGE 1-1/2"
NEW!! THK 2SRH+70L?LINEAR SLIDE CROSSED
NEW!! ROLLWAY 6207-2RSR BALL BEARING 35MM x 72MM x 17MM
BEARING F-400 CAM FOLLOWER 4"
NEW!! ASAHI PILLOW BLOCK BEARING UCX12-39 PX12 BORE 60mm
LOT OF 4!! PACIFIC BEARING FJ-13 METRIC?BEARINGS FJ FJ 13x22x32MM (NEWS)
DELTRON DEL-TRON S3-12 BALL SLIDE ASSEMBLY
BROWNING 5X693C/VPS-219G PILLOW BLOCK BEARING CAST-IRON TWO-BOLT 1-3/16"-DIA
3 NEW PIECES!! INA 6208-RS1 BALL BEARINGS 40 x 80 x 18MM
ZBF 63381-20540-71 BALL & ROLLER BEARING?40x108x30MM (NEW)
3 NEW PIECES!! SMT 77R10 SINGLE ROW BALL?BEARING 1/4" x 5/8"?x 0.196"
2 NEW PIECES!! ASAHI?MC GILL MCFR 13-SB?BEARING CAM FOLLOWER?13MM
FBJ 6208 ZZ C3 BALL?BEARING 40 x 80 x 18MM (NEW)
NEW!! FAFNIR SUPER PRECISION 2MM9102WI DUAL BEARINGS 15X32X9MM
LOT OF 2!! NTN 5209?BALL BEARING 45 x 85?x 30.2 MM (NEW)
LOT OF 4!! NSK UBLF201AJ N AV2S 2 BOLT FLANGE BEARING ID 12MM
IJK 7001ATY ROLLING?BALL BEARING 12MM x?28MM x 8MM
THK INTELLIGENT ACTUATOR 03WX-60-300 LINEAR MOTION CONTROL LONG SLIDER 300MM
4 NEW PIECES!! SMT 6903 ZZ BALL BEARING?17MM x 30MM x 7MM
2 NEW PIECES!! THK 1040T LINEAR SLIDE BEARING 40MM ASAHI
BROWNING VPS-235 MOUNTED BALL BEARING 2-3/16" (1A113A)
8 NEW PIECES!! GMB 6306 RADIAL BALL BEARING 30x72x19MM
FYH P203J PILLOW BLOCK BEARING 15 mm BORE LOT OF 2
NEW!! NSK 3313B-2ZRTNG BALL BEARING 65 mm / 2.5590 in. ID.
TORRINGTON FAFNIR DW8 FS464 CONTROL BALL?BEARING 0.5" x1.4375" x1.5" (MS27647-8)
4 NEW PIECES!! IKO LM-203242-UU LINEAR BUSHING BEARING 20x32x42MM (NEW)
INTELLIGENT ACTUATOR?THK 03WX-60-300 LINEAR MOTION CONTROL LONG SLIDER 300MM