Changing of different old model plcs with Siemens S7 300 or 400
Created by: mmkhan at: 8/29/2010 6:13 AM (5 Replies)
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| 8/29/2010 6:13 AM | |
Joined: 9/28/2007 Last visit: 12/28/2024 Posts: 235 Rating:
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Dear Experts I am a free lancer person.recently a company contact with me.they have a different type of machines on which different type of old model plcs are placed.they want to change their all plcs with siemens S7 300 or 400 PLC.now you experts tell me briefly which procedure i have to adopt to completely replace their old model and different brand plcs with siemens.please tell me briefly and step by step procedure. |
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Muhammad Munir |
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| 8/29/2010 8:45 AM | |
Joined: 10/7/2005 Last visit: 4/3/2025 Posts: 3046 Rating:
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Hello 256 I can certainly help you with the brief procedure: 1.) Program the S7('s) to have the same funtionality as the old control system 2.) Removeold control system 3.) Put in new S7 system On a more serious note, without more information about the old control system, it is impossible to give you any serious advise and I suggest you do the following: Determine the system architecture/functionality of the old control system, including - but not limited to - the type of PLC's, type and number of IO/'s (local and remote), type of SCADA system, used communciation Networks (Fieldbuses as well as PLC-PLC links and PLC-SCADA links), Machine/Plant functionality, safety requirements (more often than not, an upgrade nowadays requires also evalution of safety compliance, this is however dependant on the lawsin your country) etc. etc. Having program backups (softcopies or printouts) and electrical schematics of the old system greatly help tooin dertermining itsfunctionality and complexity. Therafter you will be in a position to make an educated decision about the best way forward (in my humble opinion anyhow). I hope this helps |
Last edited by: fritz at: 8/29/2010 9:50 AMCheers |
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| 8/29/2010 10:13 AM | |
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Joined: 9/28/2007 Last visit: 12/28/2024 Posts: 235 Rating:
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Dear Fritz 1- Can i have to write complete new PLC Program of the running System by understanding the process. 2-if i upload current PLC Program and is there any procedure that this uploaded program can work on Siemens Plc by some necessary changing like address of io modules etc. 3- Actually i just want to replace the PLC(CPU,IO Module,Communication Module) not the whole System so is there any guide to replace just plc. |
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Muhammad Munir |
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| 8/29/2010 3:32 PM | |
Joined: 9/27/2006 Last visit: 4/2/2025 Posts: 12345 Rating:
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Hello 256; Look at what is required to convert even an olderSiemens PLC to a S7-300 aor 400. There is a S5 converter available, and manuals to help out in the conversion. But if you do a SEARCH on S5-S7 conversion, you will see that just about everybody who tries it has quite a few problems in compatibiltyof standard functions, communications, HMI ,,, Actually, nothing except the vary basic binary logic converts easily. Siemens put out a TI-S7 converter package when they purchased the TI-505 line, but it was a total disaster; the distance between the 2 programming philosophies was much too great. There is still a TI-S7 library in Step 7 that holds functions originally designed for the TI PLCs (The SCALE/ UNSCALE functions used with analog signals are located there). But that is all that is left of that conversion effort. Now, if Siemens could not produce a standard conversion format inside its own brands of PLCs, imagine what needs to be done to convert a different manufacturer's material to S7. Believe me, it would be best to start from scratch, understanding the process with PLC printouts and electrical documentation, then preparing a totally new S7 program. You will save a great amount of time this way. Hope this helps, Daniel Chartier |
| 8/29/2010 4:43 PM | |
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Joined: 9/28/2007 Last visit: 12/28/2024 Posts: 235 Rating:
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Dear Dchartier now tell me one thing that which programming language is easy.STL is best or Ladder is best. actually first time i come on this side.basically i am a maintenance engineer and now for this project programming skills required. if you can tell me quick and easy way to understand the process and make a program. i will be very thankful to you. |
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Muhammad Munir |
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| 8/29/2010 5:59 PM | |
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Joined: 9/27/2006 Last visit: 4/2/2025 Posts: 12345 Rating:
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Hello Muhammad; I am afraid that if you have to ask me to recommend to you STL over LAD, you might be in over your head for this particular application. Between the different languages you have to chose the one that is most familiar to you, each one has its strength and weaknesses, and it depends on your programming style. No one else can tell you otherwise (except when some progreamming functions are not available in LAD, such as indirect addressing). The only way to do a conversion without pain is tounderstand intimately the souce PLC program, and to be very familiar with the destination PLC language. If you are not mastering either, you are facing many problems and a steep learning curve. You basicallystart a conversion the same way you begin a new program in a new plant: you study all available documentation for the process, I/O lists, P&ID diagrams, electrical panel drawings, communication schematics, in addition to the original PLC program. Then you try to understand how the process was divided up in the PLC program(by area ,by machine,by function...) and how each block or section of logic was used to control the different parts, and the I/O addresses associated. Then you re-create in your new PLC the different control blocks and document it precisely, so that the plant techs can understand and follow the new plant controls. Often you would have to bring in new I/Os and equipment that will communicate with your new PLC. If you would like to maintain some of the I/Os in your process, or other PLC-controlled equipment (drives, valve actuators...), you will have to list what is present and see if there is some way that your new PLC can talk to them, either over existing networks, Modbus for example, or new ones supported by the S7 PLC, such as Profibus-DP or Profinet (doubtful at first glance). At least give us some information on the existing system if you would like us to guide you on these issues. Some of us here might have some experience with these controllers. Hope this helps, Daniel Chartier |
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