PLC内的存储器主要用于存放系统程序、用户程序和数据等。
PLC系统程序决定了PLC的基本功能,该部分程序由PLC制造厂家编写并固化在系统程序存储器中,主要有系统管理程序、用户指令解释程序和功能程序与系统程序调用等部分。
系统管理程序主要控制PLC的运行,使PLC按正确的次序工作;用户指令解释程序将PLC的用户指令转换为机器语言指令,传输到CPU内执行;功能程序与系统程序调用则负责调用不同的功能子程序及其管理程序。
系统程序属于需长期保存的重要数据,所以其存储器采用ROM或EPROM。ROM是只读存储器,该存储器只能读出内容,不能写入内容,ROM具有非易失性,即电源断开后仍能保存已存储的内容。
EPEROM为可电擦除只读存储器,须用紫外线照射芯片上的透镜窗口才能擦除已写入内容,可电擦除可编程只读存储器还有E2PROM、FLASH等。
Star STEC 311M Pendant Operator Interface Seiki Robot Free Shipping!
Mitsubishi NF-SF 3P 60A CE 1J3B2822 86-HD Circuit Breake K55-H
Box of 12 Technical Industrial TIPHEN005 22 GAGE 1/4" Probe Points
Fanuc CPU Board, A16BB, Plastic Piece Missing,
Parker L Pneumatic Valve 24 VDC, 3/8", 3 Pos., Air Control
Lot of 1000 STMicroelectro?nics DDX-4100A13TR DDX-4100ATR-D1B T29422DH0003
9" Autocon CRT/MDI Monitor Unit, A, A, DM30-09BO-728-CLA,
HOWA JKB6H40X30-S4-RK HYDRAULIC CLAMP read description
5U4-76 Sylvania Bulletin 7305 AC Relay 4 NO Contacts 120 VAC Coil Clark
OEM Minolta QMS Black Cartridge SEALED
Honeywell Microswitch Hycal Sensing Products HTP-UT06-C08D-FJ-CN
Belden Lumberg Cable
Indramat AC Servo Drive, # TDM 1.W1,
Westinghouse 1B30035H01 Input Module Process Control Base Ovation Emerson
Fanuc PC Board, A16B / 04B Off Fanuc Wire EDM Machine,
Brand Kodak Nexpress Nekoosa Magnecote Shield Kit
Getty's Fanuc Model 20 DC Servo Motor, # 20-1/5PM-0011,
Fanuc AC Servo Amplifier Unit, # A06B-6066-H012, , 90 Day
Mitsubishi Enhanced Converter Power Supply, MDS-B-CVE-220,
International DGVAC72DN Valve
Numatics 153SA415M 152SA400M Valve Assembly
Magnetek Louis Allis 46S 5Y PCB Board
Charmilles Roboform C 200 CNC EDM PC Board,
Mitsubishi High Gain Servo Drive Unit, MDS-B-V14-20,
Fanuc AC Servo Motor, Model# 0, A06B-0513-B504 #7008, Mfg'd: 2007,
Veriflo IR401S4PBV14 Regulator with Gauge
14" Fanuc Color CRT/MD Unit, A02B-0222-C071 / MBR, D14CM-01A,
Lot of 10 INA SCE47PP Needle Roller Bearings
Total Source A8LHN/00 SY82919 Spherical Bearing
18 - Kennametal / Erickson Assorted Collets For Collet Chuck,