Program memory capacity: 8k.
Input / output points: maximum 256 points.
A scan cycle of PLC must pass through three stages: input sampling, program execution and output refresh.
PLC in the input sampling phase: first of all, in order to scan the sequence of all existing input latches in the input terminal of the state or input data read,
And write it into the corresponding input status register,
Refresh the input, then close the input port, enter the program execution stage MITSUBISHI A2SHCPU A2SHCPU AnS, QnAS bus connection, the reader to write program 2 channel connection.
Input status and input information input from the input interface,
CPU will be stored in the working data memory or in the input image register MITSUBISHI A2SHCPU.
And then combine the data and the program with CPU.
The result is stored in the output image register or the working data memory,
And then output to the output interface, control the external drive.
The response time of PLC is the interval between the time of the change of the external output signal of the PLC and the time of the change of the external output signal which is controlled by it,
Lag time, this is the time constant of the input circuit,
The time constant of the output circuit, the arrangement of the user statement and the use of the instruction,
The cycle scan mode of PLC and the way of PLC to refresh the I/O and so on MITSUBISHI A2SHCPU.
This phenomenon is called the I/O delay time effect. Type of input: DC source.
Input points: 32 points.
Input voltage: DC24.
Input current: 7mA.
Connection mode: terminal row.
Common common point: 32.
Sequential function flow chart language is designed to satisfy the sequential logic control.
The process of sequential process action is divided into steps and transformation conditions,
According to the transfer condition, the control system is distributed in the function flow sequence,
Step by step according to the sequence of actions.
Each step represents a control function, represented by the box.
In the box, the ladder logic is used to complete the task of the corresponding control function.
This programming language makes the program structure clear and easy to read and maintain,
Greatly reduce the programming workload, shorten the programming and debugging time.
Used in the system of the size of the school, procedures for more complex occasions.
Sequence function flow chart programming language features: to function as the main line, in accordance with the functiional flow of the order of distribution, clear, easy to understand the user program,
Avoid the defect of ladder diagram or other languages,
At the same time, the use of ladder language to avoid the use of ladder programming,
Due to the compllicated mechanical interlock, the structure of the user program is complex and difficult to understand,
User program scan time is also greatly reduced A2SHCPU A2SHCPU.