BASIC program running.
RS-232 2 channel, RS-422 2 channel.
How to determine the input / output device of MITSUBISHI plc.
All input devices and output devices required for the determination of the system,
To determine the I/O PLC points.
Detailed analysis of the process and work characteristics of the controlled object,
To understand the coordination between the controlled object machine, electricity and liquid,
The control requirements of the controlled object for MITSUBISHI PLC control system are put forward,
Determine the control program, to develop a design task book.
Input and output points: 2048 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 AD51-S3
AD51-S3
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 AD51-S3.
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 AD51-S3.
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.
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 logical operation instructions each account for 1 words. Timer / counter,
Shift instruction accounted for 2 words. Data operation instructions for 2~4. Input voltage range: AC100-120V/AC200-240V.
Output voltage: DC24V.
Output current: 1.2A additional power supply unit.
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.
The input and output points and types of PLC should be determmined according to the analog quantity and switch quantity of the controlled object,
Generally an input / output element to take up an input / output point AD51-S3.
Taking into account the future adjustment and expansion,
In general should be estimaated on the total number of points plus the amount of spare 20%~30% AD51-S3.
The following describes the centralized control system I/O points of the estimate.