In the 1960 of the 20th century United States introduction of programmable logic controllers (Programmable Logic Controller,PLC) instead of the traditional relay control device since the PLC have been developing rapidly, has been widely used all over the world. Meanwhile, PLC functionality has been improved. With computer technology, signal processing, control network technology and user … Continue reading What is a PLC automatic control system
What sources of electromagnetic interference in PLC control system
One, from space radiation interferenceSpace radiation electromagnetic (EMI) consists mainly of electrical equipment for power network, transients, lightning, radio, television, radar, high-frequency induction heating equipment, often referred to as radiation interference, its distribution is extremely complex. PLC systems in the RF field, it ***** to radiation interference, its influence through two paths; one is directly … Continue reading What sources of electromagnetic interference in PLC control system
Composition of the PLC configuration, CPU, I/O modules, power modules
Composition of the PLCIn terms of structure, PLC is divided into fixed and modular (modular) two. Fixed type PLC including the CPU board, I/O Board, display panel, a block of memory, power supply, these elements combine into a whole that is not removable. Modular PLC including CPU module, I/O modules, memory, power supply module, backplane, … Continue reading Composition of the PLC configuration, CPU, I/O modules, power modules
PLC program debugging
After the PLC program debugging through can only to users, or try to run. Field debugging to debug outline prepared in advance. According to the outline, step by step in an orderly manner.When you start debugging, the device may not work, not even charged. Progress step by step power available with debug, boot, loading, running … Continue reading PLC program debugging
Detailed steps for PLC system design and commissioning
(A) analysis of controlled objects control requirements andDetailed analysis of control processes and characteristics about control of interaction between mechanical, electrical, fluid, made the control requires control of PLC control system, identification of programmes, development proposal.(B) determine the input/output devicesAccording to the system requirements, and determine all of the required input devices (such as push … Continue reading Detailed steps for PLC system design and commissioning
Difference between conventional PLC and safety PLC
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
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
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
PLC ONE 