MELSECNET (II).
Coaxial circuit. Output type: transistor drain.
Output points: 16 points.
Load voltage: DC12/24.
Load current: 0.5A.
Connection mode: terminal row.
Common public end points: 8.
Structured text language is a programming language that describes a program with a structured description of the text A1SX20EU Manual A1SX20EU User's Manual.
It is a programming language similar to a high level language A1SX20EU In large and medium
Structured text is often used to describe the relationship between the various variables in the control system based on the PLC system.
Mainly used for other programming languages more difficult to achieve the user program.
The structured text programming language uses the computer description method to describe the various kinds of relations between the various variables in the system,
Complete the required function or operation A1SX20EU Manual A1SX20EU User's Manual.
Most PLC manufacturers use structured text programming language similar to BASIC language, PASCAL language or C language and other advanced languages,
But in order to be convenient, the expression methods of the statement and the types of statements are simplified.
Structured text programming language features: the use of high-level language programming, you can complete the complex control operations,
Need to have a certain level of computer knowledge and programming skills,
Higher requirements for engineering designers A1SX20EU Manual A1SX20EU User's Manual. Poor visibility and operability. Cable length 10m; used in A6TE2-16SRN.Input and output points: 4096 points.
Input / output data points: 8192 points.
Program capacity: 30K.
Basic command processing speed (LD command) s:0.15.
Integral type: the PLC components are installed together or a few pieces of printed circuit board,
And together with the power supply installed in the casing to form a single overall called the host or the basic unit, small, ultra small PLC using this structure.
Modular: PLC is the basic components of a separate module.
Medium and large PLC used this way. Easy maintenance.
Each scanning process. Focus on the input signal sampling. Focus on the output signal to refresh.
Input refresh process. When the input port is closed,
Program in the implementation phase, the input end of a new state, the new state can not be read.
Only when the program is scanned, the new state is read.
A scan cycle is divided into the input sample, the program execution, the output refresh.
The contents of the component image register are changed with the change of the execution of the program.
The length of the scan cycle is determined by the three.
CPU the speed of executing instructions.
Time of instruction.
Instruction count.
Due to the adoption of centralized sampling.
Centralized output mode.
There exist input / output hysteresis phenomena, i.e., the input / output response delay.
User program storage capacity: it is a measure of how much the user application can store the number of indicators A1SX20EU Manual A1SX20EU User's Manual.
Usually in words or K words as units. 16 bit binary number is a word,
Every 1024 words are 1K words. PLC to store instructions and data in words.
General llogical operation instructions each account for 1 words A1SX20EU Manual A1SX20EU User's Manual. Timer / counter,
Shift instruction accounted for 2 words. Data operation instructions for 2~4.