Because each brand configuration is not the same, so its selection methods are also different, the following focus on the commonly used Volkswagen brand Mitsubishi Plc selection method, we can do a reference to choose to use Mitsubishi PLC.
(i) Analysis of controlled objects and submission of control requirements
This paper analyzes the process and working characteristics of the controlled object in detail, understands the cooperation between the controlled object machine, electricity and liquid, puts forward the control requirements of the controlled object to the Mitsubishi PLC control system, determines the control scheme, and formulates the design task book.
(ii) How to determine the input/output equipment of Mitsubishi PLC
According to the control requirements of the system, determine all the input equipment required by the system (such as: button, position switch, conversion switch and various sensors, etc.) and output equipment (such as contactor, solenoid valve, signal indicator and other actuators, etc.), so as to determine the input/output equipment related to Mitsubishi PLC to determine the I/O points of PLC.
(iii) How to choose Mitsubishi PLC
Mitsubishi PLC selection includes the selection of Mitsubishi PLC models, capacity, I/O modules, power supplies, etc., as detailed in the second section of this chapter.
(iv) Mitsubishi PLC distributes I/O points and designs Mitsubishi PLC Peripheral Hardware Lines
1. Assign I/O points
Draw a connection diagram or corresponding relationship table between the I/O point of the PLC and the input/output device, which can also be done in step 2nd.
2. Design plc Peripheral Hardware Line Draw the electrical circuit diagram of other parts of the system, including the main circuit and the control circuit without entering the PLC. The electrical schematic diagram of the system is composed of the I/O Connection diagram of PLC and the external electrical circuit diagram of PLC.
The hardware electrical wiring of the system has been determined.
(v) Mitsubishi PLC Program Design
1. Program Design According to the control requirements of the system, a suitable design method is used to design Mitsubishi PLC program. The program to meet the system control requirements as the main line, one by one to implement the various control functions or sub-tasks of the program, and gradually improve the system specified functions.
In addition, the program should usually include the following: 1) Mitsubishi PLC initialization program. After Mitsubishi PLC on the power, generally have to do some initialization operation, for the start of the necessary preparation, to avoid the system error action.
The main contents of the initialization program are: To clear some data areas, counters, etc., to recover the data required for some data areas, to position or reset some relays, to display some initial state, and so on. 2) Mitsubishi PLC detection, fault diagnosis and display procedures.
These programs are relatively independent and are generally added when the program design is basically complete. 3) Mitsubishi PLC protection and chain procedures. Protection and linkage are indispensable parts of the program and must be carefully considered.
It avoids the confusion of control logic caused by illegal operations.
2. Mitsubishi PLC Program simulation and debugging The basic idea of program simulation and debugging is to simulate the actual state of the field in a convenient form, and to create the necessary environmental conditions for the operation of the program.
According to the different ways of producing field signals, there are two forms of simulation and debugging, such as hardware simulation method and software simulation method.
1) Hardware simulation method is the use of some hardware equipment (such as another plc or some input devices, etc.) to simulate the production of field signals, and these signals are hard wiring to the input of the PLC system, its timeliness is strong. 2) Software simulation method is in Mitsubishi PLC to write an additional set of simulation procedures, simulation to provide field signals, it is simple, but the timeliness is not easy to guarantee.
In the process of simulation debugging, the method of segmented debugging can be used, and the monitoring function of the programmer may be used.
(vi) Mitsubishi PLC hardware Implementation Hardware implementation is mainly for the control cabinet (Taiwan) and other hardware design and site construction.
The main contents are as follows:
1) Design the control cabinet and the operator table and other parts of the electrical layout diagram and installation wiring diagram.
2) Design the electrical interconnect diagram between the parts of the system.
3) According to the construction drawings for the site wiring, and carry out a detailed inspection.
Because programming and hardware implementation can be carried out simultaneously, the design cycle of Mitsubishi PLC control system can be greatly shortened.
(vii) Mitsubishi PLC online Commissioning Online debugging is a further online tuning of the program that will be simulated and debugged. The online debugging process should be gradual, from Mitsubishi PLC only connected to the input equipment, reconnect the output equipment, and then connected to the actual load and so on gradually debugging. If the requirements are not met, the hardware and procedures are adjusted.
Usually you only need to modify some programs. After all debugging is complete, deliver the trial run. After a period of operation, if the work is normal, the program does not need to be modified, the program should be solidified into the EPROM, in case the program is lost.