Siemens and other Western PLCs vs. Japanese PLCs

Andreik

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Join Date
Mar 2009
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Makati City
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Good day,

I am a Japanese PLC user (Omron, Keyence and a little bit of Mitsubishi).

I just wanted to know how different the Programming schemes and complexity are between Asian and Western PLCs. I am also interested in learning these Western PLCs especially the well known Siemens.

Thank you.
 
I have programmed a little in Omron, but have not experience with the other Japenese PLC's. I generally program with the AB platform. I have experience with Siemens and some others. With that disclaimer, I found the Omron to be like the difference in programming with Assembler to using something like C+. The instruction set in the AB seems much easier to use. You can do many things in the AB with one instruction that take a bunch of ladder in the Omron. I read a post last week concerning a Mitsubishi where the poster was trying to perform a simple number conversion that would have been automatically performed in the AB.

Russell
 
I have programmed a little in Omron, but have not experience with the other Japenese PLC's. I generally program with the AB platform. I have experience with Siemens and some others. With that disclaimer, I found the Omron to be like the difference in programming with Assembler to using something like C+. The instruction set in the AB seems much easier to use. You can do many things in the AB with one instruction that take a bunch of ladder in the Omron. I read a post last week concerning a Mitsubishi where the poster was trying to perform a simple number conversion that would have been automatically performed in the AB.

Russell

You can ALSO do many things in OMRON with one instruction that takes a bunch of ladder in an AB.

A simple example is the laborious OSR/OSF arrangement in Rockwell software. In OMRON just change parameter of the instruction - NO ADDITIONAL LADDER REQUIRED!!(n)
 
there are differences between controllers and programming software. they all have good and bad sides.

if you want to learn siemens, so i recommend to get both software and plc and see how you like it.

people that have worked on other platforms usually cringe when start working on siemens because even simple things are no longer so simple (for example indirect addressing, horribly slow refresh etc).

on the other hand people who started on and mostly use siemens often like it because after all it is a powerful platform and they are already familiar with. also support must be better in Europe than here.
 
in response to russel,

yes there are things that are much easier in AB but it goes both ways. one shot instructions are one good example that japaneese do way better. also in omron you can force any signal not just i/o, AND you can download comments for example.

similar goes for mitsubishi. btw. i was just helping someone read floating number on older Mitsubishi micro plc that didn't support floats. i consider that conversion rather basic, it's just bit manipulation after checking out format of floats on internet (i've never done this conversion before, i was just curious to try it out and it was straight forward). anyone calling himself programmer should produce working code in a jiffy (not everyone working with plcs is familiar with boolean operators, masks etc.). clearly swapping that controller with more recent unit (cost $400-$800) is one way to handle it but that's not always worth it (specially if you are just reading single number comming from some other device).

some things japanese have done very well (boolet proof hardware, no defects like from AB or Siemens), there are things that they improved a lot (manuals, web presence etc. Omron has much improved software that has everything but kitchen sink etc.) but they could do more:

Both still need to work on translations. For example to select or configure programming port on PC side, one has to use menu option called "Change PLC". Omron for example also has mess of data tables that are not even named properly or one cannot use them as named. for example CIO or D/DM or T/C etc. (you cannot enter address as "CIO1.00" or "I:1.00", it has to be "1.00") system flags are different on different controllers, datatables sometimes have gaps and they (used to) push BCD (wasted range).

Mitsubishi has nice hardware and powerfull instructions but they have been lagging with software updates - a lot. Current GX still looks very old, newer software is in use in Japan for some time now but for some reason they are slow to introduce the same thing to North America. One thing I don't like is project file - it is not one file, it is tree of folders and files. imagine MS excel file format that instead of single document uses folders and bunch of files. I just started looking into FX series controllers (micros) and noticed amazing limitation - whole application has to be in just one ladder. this is just horrible. i've seen this before on the A series but i didn't think this would still be an issue. on FX2N platform configuration of the ENET adapter uses few registers per connection. They support eight connection but settings for each are scaterred all over the D datatable. for example registers that configure first connection are in D1000 range, connection2 is in D2000 range etc. this is VERY ugly. proper way is to have dedicated system area for hardware setup (com port settings, ethernet settings etc.).

Despite all limitations both of them chug along pretty good and familiarizing doesn't require big time investment.
 
hello Kabayan.

well, i have been also using jap.(asian) PLC's once. but now i have changed to Westerns PLC because of the following reasons :

1. japanese PLC's are usually NPN type of PLC's while western PLC's are PNP type.
2. jap PLC are more easier and affordable to use while western
PLC are some kind of expensive (considering small projects)
3. western PLC are more rugged than asian PLCs.
4. there is no problem having networking connection using western PLC because they are supported by the ff:
*profibus
*device net

5. when it comes to programming, using western PLCs are more complex than asian PLCs.


i hope my idea would help you kabayan.
:geek:
 
I think that
Japanese are typically smaller, more energy efficient, end more reliable.
European are technically more impressive, has more performance, but also have issues with the ease-of-use.
American are bigger than the others, use more energy, and has more crome.
 
Wow I guess I left this thread and kinda forgot about it. Nothing like passion when it comes to PLC's. We all really need to get a life..

I am not sure I would base ease of use around Oneshots as an example. I guess I never really thought of it as a issue. Frankly I just dont have to use oneshots all that much. The commands I do use I found lacking in the Omron. Been a while so maybe things have improved.

I also have not really had any problems with AB hardware defect issues. Maybe I have just been lucky? In 20+ years I can only think of two processors that died. One was hosed down with water and the other was in a small cabinet the client had put outside in 100F weather. Smokey... The SLC platform does like to burn outputs if not installed properly.

Downloading the documentation I will say is nice; however, the tradeoff is the memory it eats.

Something that was mentioned breifly, I think, is support. We cant get support for Seimens and if we do it stinks. Our rep is all but useless (now I should get all kinds of wonderful comments). However, the system is a solid system. I guess i need to add that our Omron guys are actually pretty good. Our Rockwell support here is fantastic. Before you make any choice you need to find out what the support level is in your area. No matter how wonderful the hardware and software are, lack of support when you have to have it can make any system difficult.

Russell
 

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