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 A171SCPU MITSUBISHI A171SCPU The telephone line of the interface module is connected with the peripheral equipment.Type of input: DC leakage.
Input points: 64 points.
Input voltage: 12/DC24.
Input current: 2/5mA.
Connection mode: terminal row.
Common common point: 32 A171SCPU MITSUBISHI.
Functional block diagram language is a kind of PLC programming language, which is similar to digital logic circuit.
The function module is used to represent the function of the module,
Different function modules have different functions.
Functional module figure programming language features: functional block diagram programming language is characterized by a functional module for the unit,
Analysis and understanding of the control scheme is simple and easy: function module is to use graphical form of expression,
Intuitive, for a digital logic circuit based on the design of the staff is very easy to master the programming;
Control system with complex scale and complex control logic,
Because the function module diagram can clearly express the function relation, the programming debugging time is greatly reduced A171SCPU MITSUBISHI. The main unit of the AS-i system
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.
This phhenomenon is called the I/O delay time effect A171SCPU.
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.
And then combine the data and the program with CCPU A171SCPU.
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.