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 A985GOT-TBA Hardware Manual A985GOT-TBA User's Manual A985GOT-TBA A3VTS with additional floor.
Switch volume control is designed to,
According to the current input combination of the switch quantity and the history of the input sequence,
So that PLC generates the corresponding switching output,
In order to make the system work in a certain order A985GOT-TBA Hardware Manual A985GOT-TBA User's Manual.
So, sometimes also known as the order control.
And sequential control is divided into manual, semi-automatic or automatic.
And the control principle is decentralized, centralized and hybrid control three.
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 A985GOT-TBA Hardware Manual A985GOT-TBA User's Manual.
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 hystteresis phenomena, i A985GOT-TBA Hardware Manual A985GOT-TBA User's Manual. e., the input / output response delay.
System program memory for storing system program,
Including management procedures, monitoring procedures, as well as the user program tto do the compiler to compile the process of interpretation A985GOT-TBA Hardware Manual A985GOT-TBA User's Manual.
Read only memory. Manufacturers use, content can not be changed, power does not disappear.