8 slot, PID special substrate.
When the programmer input programinto the user program memory,
Then CPU according to the function of the system (the system program memory to explain the compiler),
Translate the user program into PLC internally recognized by the user to compile the program.
Relay output interface circuit of PLC
Working process: when the internal circuit output digital signal 1,
There is a current flowing through, the relay coil has a current, and then the normally open contact is closed,
Provide load current and voltage MITSUBISHI PLC Programming Manual A4UCPU
When the internal circuit outputs a digital signal 0, there is no current flowing through it,
The relay coil does not have a current, and the normally open contact is broken off,
A current or voltage that is disconnected from the load MITSUBISHI PLC Programming Manual.
It is through the output interface circuit to the internal digital circuit into a signal to make the load action or not action.
I/O points is an important indicator of PLC.
Reasonable selection of I/O points can not only satisfy the control requirements of the system,
And the total investment of the system is the lowest MITSUBISHI PLC Programming Manual.
The input and output points and types of PLC should be determined according to the analog quantity and switch quantity of the controlled object,
Generally an input / output element to take up an input / output point A4UCPU Programming Manual.
Taking into account the future adjustment and expansion,
In general should be estimated on the total number of points plus the amount of spare 20%~30% A4UCPU Programming Manual.
The following describes the centralized control system I/O points of the estimate. Output type: transistor drain.
Output points: 16 points.
Load voltage: DC12/24.
Load current: 0.1A.
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 A4UCPU Programming Manual.
It is a programming language similar to a high level language. 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.
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 expressionn methods of the statement and the types of statements are simplified A4UCPU Manual .
Structured text programming language features: the use of high-level language programming, you can complete the complex control operations,
Needd to have a certain level of computer knowledge and programming skills,
Higher requirements for engineering designers MITSUBISHI PLC Programming Manual. Poor visibility and operability.