PLC dealing with so many years, often encounter some beginners PLC asked about the difference between Siemens PLC and Mitsubishi PLC, there are many novice distressed in the choice of which brand to learn, here I put my personal views to share with you.
First, the programming concept is different
Mitsubishi plc is a Japanese brand, programming intuitive and easy to learn, it will be more relaxed, but more instructions. The Siemens plc is a German brand, instruction is more abstract, more difficult to learn, but less instruction, so learning Mitsubishi and learning Siemens cycle is the same.
Personally think that Mitsubishi (Japan’s high-end brand) PLC software at least five years behind Siemens, medium and large for the time being not to mention, take advantage of Mitsubishi’s minicomputer FX series and Siemens S7-200 series compared to Siemens have the following Advantage:
1, Mitsubishi’s programming software From the early FXGPWIN to the recent GX8.0 (I know the latest), and all Japanese brands, the software programming ideas is a single vertical structure from top to bottom, and Siemens MicroWIN It is both vertical and horizontal structure, and subroutine support for local variables, the same function only need to compile a program can be, greatly reducing the development difficulty and time.
2, S7-200 has always supported a strong floating-point operations, programming software directly supports the decimal point input and output, and Mitsubishi until recently introduced the FX3U series have such a feature, the previous FX2N series of floating-point functions are false.
3, S7-200 analog input and output procedures is very simple and convenient, AD, DA value can be accessed directly without programming, Mitsubishi FX2N and its previous series require a very cumbersome FROM TO instruction. FX3U now support this feature down, but a full five years later even more.
4, of course, Mitsubishi FX2N series also has its own advantages, first, high-speed counter instructions than the S7-200 convenient, and second, 422 PPI port Siemens than the real skin (because 200 series PPI port is non-optical isolation, non-standard operation and Imitated programming cable may cause serial port damage).
The above comparison is only a minicomputer, as for the Siemens 300 and 400 series and the larger TDC series, there is no need to say anything more.
Learn PLC, Mitsubishi is very easy to use, because straightforward thinking is simple, but from a learning point of view, certainly Siemens is better.
Second, the chip is different
This is mainly reflected in the capacity and speed of operation. Siemens CPU226 program capacity of 20K, data capacity of 14K; and Mitsubishi FX2N only a total of 8K, but later the 3U is improved.
Siemens CPU226 and CPU224XP standard configuration 2 485 or PPI port, the maximum communication speed 187.5K; and Mitsubishi FX3U before all series are a 422, and the speed is 9.6K. If you need to even a smart meter what you have to buy another special module FX2N0-485BD. And two communication port can be a connection to download a data line to connect the touch screen debug program, or you have to unplug the touch screen data cable and then connect the touch screen data line, back and forth to adjust the program is very troublesome.
Third, the strengths of different control
The strength of Siemens is the process control and communication control. Siemens analog module is cheap and the program is simple. However, Mitsubishi analog module is expensive and the program is complicated. Siemens is also easy to communicate and the procedure is simple. Mitsubishi is weak in this function. (Today’s forwarding code is: Billion dimensional quality assurance: half a replacement, 5-year warranty, lifetime maintenance)
Mitsubishi’s advantage lies in the discrete control and motion control, Mitsubishi instruction rich, dedicated positioning instructions, easy to control the servo and stepping, to achieve some complex action control is also Mitsubishi’s strengths, and Siemens in this piece is weak , There is no dedicated instruction, servo or stepper positioning control can not be achieved, but the program is complicated, control accuracy is not high.
For example, a certain device is just some action control, such as manipulator, you can choose Mitsubishi’s PLC, a device has servo or stepper for positioning control, also choose Mitsubishi’s PLC. Such as central air conditioning, sewage treatment, temperature control, such as analog to have a lot of analog to be selected Siemens PLC more appropriate, a lot of instruments on-site data to collect communications using the communication, the election of Siemens good control.
Therefore, different devices for different control methods, we have to choose a reasonable PLC, with its strengths, to avoid its shortcomings.

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