Trends in embedded plc IO module

A developmental path is the development of PLC and HMI combination of hardware / software integration for the target platform , taking advantage of CASE tools, combined with various types of embedded chip development platform and a variety of input / output channels of the hardware circuit library , designed for the development of customized electromechanical equipment , with a special nature ODM PLC. This indicates that the embedded PLC has much Nanda Programmable industrial controller plc  room for development . Embedded PLC has a broader space for development in our country, first of all it is very conducive to the development of China's two major characteristics play automation industry : There is a very strong market for the electrical and mechanical equipment for the foundation , and has enough global optimal cost design and development team . We can at the lowest cost , high quality, according to custom requirements of the design , production and electromechanical equipment for embedded PLC, instead of the generic PLC.
Meanwhile, the various aspects of functional embedded PLC hardware , software, human-machine interface , communications, design  Plc logic controllers flexible, easy to cut , closer to the requirements of various grades of electrical and mechanical equipment . Embedded PLC technology based entirely on the basis of embedded systems can be used with . SoC chip , embedded operating systems and compliance with IEC61131-3 programming language standard programming environment and other advantages, making it very easy to find on the market .
In the current environment is not difficult to develop a common PLC technology breakthrough, but to seize the market requires a lot of financial and human resources invested . In the market has been one of the few large companies to carve solid today, go this route seems to be less effective. Our small PLC gratifying progress in recent years, there are practical , too, proved this judgment.

output module plc programming optimization techniques: improved program 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.

How to handle input module plc plc signal

PLC analog input module to analog ( continuous signal ) is converted to digital ( discrete signal ) usually after : sampling and quantization two processes. For example, "analog" is the distance from the PLC Programmable industrial controller plc origin of moving objects , " sampling " is equivalent with a camera shooting, at regular intervals on the " capture " a picture , as long as a suitable interval , the picture is also through these intermittent energy about the trajectory of the object. " Quantify " the process is to put these photos in various locations of objects are classified into a limited number of specified location , such as 1 meter , five meters , 10 meters ..... , namely the continuous position data . " format " ( converted to CPU can recognize and handle data format ) , to facilitate the next step of CPU processing . Siemens S7-300PLC for example , 0-20mA input corresponds to 0-27648 , namely PLC internal " 1" represents (20/27648) mA; corresponds to the input of  PLC Power supply module plc 5mA, internal PLC is represented by 6912 .
After the analog to digital conversion , the PLC can be carried out in a variety of digital processing ( including math, logic operation ) , according to the practical application of specific processes identified . For example , determining a first analog input channels of digital value is greater than 6912 ( corresponding to 5mA), meet the conditions , the output of a switch or a digital computing . If necessary you can also go through the digital analog output module ( inverse process) an analog output .