Safety programmable logic controller (PLC) is designed for special-purpose machines and equipment used for critical control and safety applications. These controllers are usually the safety instrumented system (SIS) as part of use in detecting potentially dangerous processes in industrial environments. If danger is detected, SIS applications automatically, switch to the process safety. Here, the user … Continue reading Difference between conventional PLC and safety PLC
Category: plc program
PLC capacity formula
PLC including I/O points and user storage capacity the capacity of two aspects.Amount of storage capacity that is required by the user program is not only associated with the functions of the PLC system, but also with the capabilities of the program level. An experienced programmer and a beginner, when completing the same complex functions, … Continue reading PLC capacity formula
Basic structure of the modular PLC
S7-300/S7-400 belongs to the modular PLC, main frame, power supply module, CPU module, signal modules, modules, interface module, communications processors, equipment and programming, a variety of module is installed in a rack. Through communication interface in the CPU module or module, on the PLC are connected to the communications network, you can communicate with other … Continue reading Basic structure of the modular PLC
Difference between DCS control system and PLC control system
Differences from the basic structure of the DCS and PLC, DCS distributed control system of English (TOTALDISTRIBUTED CONTROL SYSTEM) for short. Refers to the control of dispersed risk, manage and display set. Late 60 programmable controller was developed as a logical operation (Programmable Logic Controller). Referred to as PLC. Mainly used in the automotive industry. … Continue reading Difference between DCS control system and PLC control system
Basic instruction of PLC and characteristics
PLC programming languages and computer languages, have distinctive features, which is different from a high-level language, and with the General Assembly, it is both easier to write, and to meet the requirement to debug. At present, there is no programming language to the manufacturers of products are compatible. If Mitsubishi products has its own programming … Continue reading Basic instruction of PLC and characteristics
PLC maintenance essentials and fault analysis
A, operating environment to ensureSince the PLC for precision electronic products, automation and control system requires long uninterrupted run, thus PLC environment demanding, dust-proof, fireproof, waterproof, heat, lightning, electrical control room general arrangements have double glazing, install water cooling air-conditioning on the second floor, electronic room temperature control in 28 degrees; Dust is the PLC … Continue reading PLC maintenance essentials and fault analysis
Siemens PLC data type and address
In the following example to MD1,MD34 to MD2 MD30 (see the following figure). I entered in the simulation at MD1 30.0, press ENTER to appear 11.8953. I have no problem to do it by the book addresses. I would like to ask this MD30 into MD1,MD34 to MD2 relationship? These can literally change the address? Here … Continue reading Siemens PLC data type and address
STEP7 common shortcut keys
CTRL + l downloadCTRL + d module informationCTRL+i modeCTRL + ALT + r reference dataALT + entre object propertiesF2 normally open contactF3 normally closed contactF7 coilCTRL + r to insert segmentsALT +F9 inserted into the empty boxCTRL+1 LAD ladder diagramCTRL+2 STL STLCTRL+3 FBD function block diagramCTRL +Q symbolic expressionsCTRL +SHIFT +Q symbol informationCTRL +ALT +T … Continue reading STEP7 common shortcut keys
Setting the S7-300 address register address
OPN DB100L 0LAR1L 3500ITD RLD 3+AR1 L DBW [AR1, P#0.0] //Read DB100.DBW3500But after the address >4095, with 4096 values RLD 3 is greater than or equal to the value of 32768Error value in the AR1 (great value).So that there are 3 to the left has been unable to obtain the correct address.Ask you what other … Continue reading Setting the S7-300 address register address
Siemens RCV/XMT order questions and answers
S7-200 communication ports can be set to free port mode of the CPU. Freedom of choice of mode, the operation of the user program can completely control a communications port, communications protocols are completely controlled by the user program.S7-200 communication port on the CPU in the electrical RS-485 is standard on half-duplex serial communications port. … Continue reading Siemens RCV/XMT order questions and answers
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