The role of output modules plc

Fire alarm, the alarm controller output module needs to start by the linkage of external control devices, such as ethernet module plc control valve, sending valve, fire shutter doors, fans, alarm, etc., and to accept the action device to answer.
output module plc connected to the bus loop controller can be installed in the vicinity of the control equipment can also be installed in the plc high-speed counting module inside the terminal module. Electronic writing code, you can live encoding. Ji-output control logic output module can be completed according to the project situation programming. When the controller receives the alarm signal to the detector, based on pre-programmed into the procedure, the controller via the bus output control signal to the interlocking modules, output modules linkage needs to start fire-fighting equipment; action after the device receives a reply signal.

IO module, also known as the PLC control module

plc IO module is also called a control module, can be output when the control request signal or a switching signal to plc communication module operation of the controlled device, and may receive a feedback signal from the device to the host to report to the fire alarm system linkage important part of the input and output modules on the market can provide a pair of passive normally open / normally power supply module plc contacts for controlling the controlled device, some manufacturers of modules through parameter setting, set to active output (eg Bay GST-LD-8301), there are also double the corresponding input and output modules, the input and output modules, and so more.

Input Module plc's shortcomings

input module plc Disadvantages: module mechanism to bring safety hazard
1, the intercept system calls.
2, modify the output symbol table.
3, by modifying the system calls the plc temperature module themselves hidden.
4, redirect file operations.
5, modify the file owner.
6, plc controller suppliers processes.
7, the executable file redirection.
8, calling sys_socketcall by modifying the system, making the system after receiving the specified data packet open the back door
9, TTY hijacking.
10 virus.

Output modules plc explanation

output module plc, known as members, is a collection of individually named and independently able to complete certain functions of plc program logic controller statements (ie, aggregate program code and data structures). It has two basic characteristics: internal features and external features. Wherein the external plc digital input output module module with means to contact the external environment (i.e., program modules or other way to call the module, including input and output parameters, global variables referenced) and functional modules; internal environment is the internal characteristics of the module having the characteristics (i.e., the local module data and program codes).

plc io module is divided into several modules by function

plc io module is divided into several modules by function
plc IO module is divided into several modules according to function, such as CPU modules, input modules, output modules, power modules, and so on. The module features a communication modules plc mainframe is more some kind of modules and therefore relatively more. This can also be said to be the trend. At present, some medium-sized machine, the module features also tend to single species also increases Township. If the same OMRON Corporation intelligent plc series PLC, H machine CPU unit to contain the power, and put the power ceded Ha machine, a separate power supply module.

How to increase running speed

1 : According to the actual needs of the project , functional block planning, writing subroutines

In the PLC program subroutines are relatively  Nanda Programmable industrial controller plc independent control purposes for a number of specific preparation . CALL subroutine call instruction is executed , such as when a subroutine call if the condition is not met , the program scans performed in the main program only , and not to scan this subroutine , which reduces scan time unnecessarily . 2 : Use a word or double word reportedly gave DO -point method to control output
In the application of PLC will usually have a lot of output control , with the word, or double word reportedly gave DO -point method to control the output can improve the speed , as long as according to the requirements of practical application, a reasonable allocation of the output address , change control output control word , you can greatly reducing the number of steps PLC program execution , thus speeding up the running Nanda china industrial automation plc  speed of the PLC .

3 : Pulse trigger SET, RESET
  PLC, using the SET command is executed only once , do not run this command every scan , it is suitable for use with pulse output (PLS / PLF) instructions for use . Some engineers ignore this problem , the use of conventional methods to drive the SET command , inadvertently increasing the PLC program scan running time.

Input Modules plc Product Design:

input module plc has the following mechanical properties: 

Compact design: 

Rugged plastic enclosure inside include: Green plc temperature control module, status indication for signal input. Before connecting socket, through the front door to protect the label area on the front door. Easy installation: 

No slot rules; enter an address determined by the slot. 

When used in conjunction with a bus in the ET plc logic controller modules can be hot-swappable. User-friendly wiring. 

With 8,16,32 or 64-channel modules.

Definition of the PLC

There are many definitions PLC. International Electrotechnical Commission (IEC) is the definition of the PLC: Programmable Logic Controller is a digital electronic computing operating programmable logic controller system, designed for applications in industrial environments. It uses a programmable memory, used in its internal storage to perform logical, sequential control, timing, counting and arithmetic operations such as operating instructions, and through digital and analog inputs and outputs, control types machinery or production processes. Programmable logic controller and related equipment, all with industrial control systems should be easy to form a whole, to expand the principles of the design of its functions. The mid-1980s to the 1990s, is the fastest growing PLC period, the annual growth rate has been maintained at 30 to 40 percent. During this period, PLC capability in handling analog and digital computing power, man-machine interface capabilities and network capabilities have been greatly improved, PLC gradually entering the field of process control, in some applications in the field of process control to replace the dominant DCS systems. PLC has the versatility, ease of use, wide adaptation, can be * high anti-jamming

plc power supply module

capability, programming and simple. PLC in the industrial automation and control especially in order to control the position, in the foreseeable future, can not be replaced.

History of PLC

In the industrial production process, a lot of switching sequence control, which in accordance with theplc programmable intelligent controller conditions of the order to move a logical and controlled chain protection action in accordance with the logic of relations, and a large number of discrete data collection. Traditionally, these functions are controlled by pneumatic or electrical system to achieve. 1968 American GM (General Motors) companies to replace the electrical control device, following the requirements of the second year, the United States developed a digital control device company based integrated circuits and electronic technology, for the first time using procedural means used in electrical control, which is the first generation of high speed counter plc, said the Plc high speed counting modules Programmable Controller (PC). After a personal computer (referred to as PC) to develop, in order to facilitate, but also to reflect the high speed counter plc's features, programmable logic controller named Programmable Logic Controller (PLC), and now, still often referred PLC PC.

The role of output modules plc

Fire alarm, the alarm controller output module needs to start by the linkage of external control devices, such as ethernet module plc control valve, sending valve, fire shutter doors, fans, alarm, etc., and to accept the action device to answer.
output module plc connected to the bus loop controller can be installed in the vicinity of the control equipment can also be installed in the plc high-speed counting module inside the terminal module. Electronic writing code, you can live encoding. Ji-output control logic output module can be completed according to the project situation programming. When the controller receives the alarm signal to the detector, based on pre-programmed into the procedure, the controller via the bus output control signal to the interlocking modules, output modules linkage needs to start fire-fighting equipment; action after the device receives a reply signal.