(1)配置方便:可接控制系统的需要确定要使用哪家的PLC,那种类型的,用什么模块,要多少模块,确定后,到市场上定货购买即可。
(2)安装方便:PLC硬件安装简单,组装容易。外部接线有接线器,接线简单,而且一次接好后,更换模块时,把接线器安装到新模块上即可,都不必再接线。内部什么线都不要接,只要作些必要的DIP开关设定或软件设定,以及编制好用户程序就可工作。
(3)编程方便:PLC内部虽然没有什么实际的继电器、时间继电器、计数器,但它通过程序(软件)与系统内存,这些器件却实实在在地存在着。其数量之多是继电器控制系统难以想象的。即使是小型的PLC,内部继电器数都可以千计,时间继电器、计数也以百计。而且,这些继电器的接点可无限次地使用。PLC内部逻辑器件之多,用户用起来已不感到有什么限制。一考虑的只是入出点。而这个内部入出点即使用得再多,也无关紧要。大型PLC的控制点数可达万点以上,哪有那么大的现实系统?若实在不够,还可联网进行控制,不受什么限制。PLC的指令系统也非常丰富,可毫不困难地实现种种开关量,以及模拟量的控制。PLC还有存储数据的内存区,可存储控制过程的所有要保存的信息。……总之,由于PLC功能之强,发挥其在控制系统的作用,所受的限制已不是PLC本身,而是人们的想象力,或与其配套的其它硬件设施了。
弥年不得意,新岁又如何?
念昔同游者,而今有几多?春色无情故,幽居亦见过。
YOKOGAWA PR20-S-05-05-T2*B PH ELECTRODE D530353
COPES VULCAN 860008 MICRO/C PCB CIRCUIT BOARD REV B D538201
BARNSTEAD/THERMOLYNE 01293 SOLID STATE LOW WATER CUTOFF 115V-AC 2A D557061
TECHECOLOGY C1190B TRANSLATOR PCB CIRCUIT BOARD CARD D534083
WESTRONICS CB100078-04 PCB RELAY CIRCUIT BOARD REV B D539269
HOBART 367563B 36756306 PCB CIRCUIT BOARD MODULE D557517
FUJITSU E660-2508-T181 CABLE-WIRE D523702
PHOENIX CONTACT MINI-PS-100-240AC/10-15DC/2 2938756 POWER SUPPLY D546723
PHOENIX CONTACT 5602444 16 CHANNEL RELAY MODULE PCB CIRCUIT BOARD D557966
WESTINGHOUSE ITH 1955594 FAULT DETECTOR RELAY D557892
HONEYWELL 910AEA031 MICRO SWITCH ILLUMINATED SELECTOR SWITCH D535734
GE 16SB1B11X2 TYPE SB-1 BREAKER ROTARY CONTROL SWITCH D583858
CLEVELAND GEAR KL5-11624 FARVAL TIMER 0-30MIN 120V-AC D584146
WENGLOR IB040DE65UB3 INDUCTIVE PROXIMITY SENSOR SWITCH D572713
NACHI RTC221 ROBOT TEACH PENDANT CONTROLLER D582669
WESTERN DIGITAL WD3200AAJB-00J3A0 320GB PATA/8MB CACHE HARD DRIVE D581444
AVENTICS R412010712 250V-AC 0.2-16BAR PRESSURE SWITCH D577283
PEPPERL FUCHS 037368 KFA6-SR2-EX1.W K-SYSTEM SWITCH AMPLIFIER 230V-AC D584258
IWC 6M-1401-03 14 AWG 600V-AC RED CABLE-WIRE 350FT D573785
DUNGS 217-337A GML-A2-4-4 GAS PRESSURE SWITCH 1IN-20IN-WC 120V 10A D574213
SIMPLEX 562-907 FIRE ALARM AMPLIFIER CIRCUIT BOARD D578769
MERLIN GERIN 6739904 6739817XD-2E ALEZ US CIRCUIT BOARD D582277
HYUNDAI HC20201NY-LY-30 PCB CIRCUIT BOARD DIS**Y MODULE D575809
RK ELECTRIC CSRA-115A-2-5-AR 115V-AC RELAY D575177
WESTINGHOUSE 293B255A20 TYPE SG AUXILIARY RELAY D582953
MILLTRONICS AO-10 230V-AC ANALOG OUTPUT MODULE D582821
IFM EFECTOR OG5114 OGT-FPKG/V4A/US DIFFUSE REFLECTION SENSOR 10-36V-DC D575998
PEPPERL FUCHS NJ20-U2-A2 PROXIMITY SENSOR 10-60V-DC 2A AMP D576026
ALLEN BRADLEY 1492-IFM40F-FS24-4 INTERFACE MODULE SER A D583236
AUTOMATIC SWITCH CO 106S140 SWITCH 115V-DC D583710
GE FANUC IC200MDL140A VERSAMAX 8PT INPUT MODULE 120V-AC D584176
GAI-TRONICS 712-101 REMOTE HANDSET/SPEAKER AMPLIFIER D589041
ALLEN BRADLEY 855T-B24SA3 SINGLE TONE SOUND MODULE 24V-AC SER C D588683
AGASTAT 2412PD TIMING RELAY 2.5-50 SECONDS 120V-DC D592548
SOR 5NN-K3 PRESSURE SWITCH 25-240PSI D584440
CROUZET GNR45DHZ COOLTECH SOLID STATE RELAY 48-600V-AC 45A D585096
ALLEN BRADLEY 1492-PD31123 POWER DISTRIBUTION BLOCK 600V-AC SER B D591119
GOULD S975 MODBUS II COMMUNICATION PROCESSOR D593214
HARBOUR INDUSTRIES RG 178 BNC TO MICRO HI-TEMP COAX 75FT CABLE D594142
SQUARE D 8501XDO20V62 CONTROL RELAY SER A 115/125V-DC D541672
MERRICK BMKM21689-1 LT104 REV 3 PCB CIRCUIT BOARD D537824
BENTLY NEVADA 330930-065-03-00 3300XL NSV EXTENSION CABLE D565190
VALMET A4180070V1.0 50FT LENGTH KAJAANI SENSOR CABLE-WIRE D562486
PHASE DYNAMICS 2000-00026-000A 02223 POWER SUPPLY BOARD D562852
FMC FC4028-A8 SYNTRON RECTIFIER PCB CIRCUIT BOARD D562765
DREXELBROOK THE POINT PXLX 19-250V-AC LEVEL SENSOR D560052
HARBOUR INDUSTRIES RG 178 BNC TO MICRO HI-TEMP COAX CABLE 75FT D563061
STEARNS 95506 BRAKE COIL D564451