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Guest Wayne Hollis

AGV data log

7 posts in this topic

Hello my name is Wayne Hollis and I’m an apprentice maintenance engineer at a company called Ricoh Products Limited Based in the UK and I am looking for help with some data logging. I would like to time stamp events, but because I would like to log a large amount of events I’m not sure of the best way to go about it. There are 43 different types’ events Every event could happen up to 25 times in one 8.5 hour time period I would like to log identification for each different event I don’t know if decimal is better than BCD? And the time the event happened HH/MM/SS. I believe I could do it but I think it might be crude and I would use 2 words (DM's) for every event. I would move the contents of AR18 to one word and combine two nibbles from AR17/8-15 and a data area with my event number (0-43). Then I would store those else where. I would have to use indirect addressing to point to where I would like them to be stored I think, and every time there was an event that address would have to increment up by 2. Im not that confident and i'm not really sure what I am doing but I know what I want to achieve, just not how to get there. I believe it could be done this way but im sure, I would run out of memory fast I think. Any help and direction would be very gratefully received (i attached a pic of the control pannel too?) Regards Wayne hollis

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There are ways to solve your problem and it depend how you will use or present data later on. The easiest and cheapest way to log events with time/date stamp on it, is use a serial printer connected to the PLC. In any event, the PLC will dump the data immediately to the printer. With this setup, less memory of the PLC will be needed with minimal programming. You can also use DDE in Excel to log data for you, very common in Omron PLC. If you have money to spend, buy a third party SCADA software and hook it up to your PLC, everything you need in logging you can find it there and more. And if you really want it hot, use Industrial PC to run your application, all events you can save in the hard drive.

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Your logic is correct and at Omron, there is no difference between decimal and BCD. Combining SS and event data in one word is legitimate and I would suggestMOVD to accomplish this. Looking at the photo, it looks like you have a CPU21. There are only 1024 DM registers in that PLC. 43 events * 25 per day= 1075 occurences * 2 registers = 2150 DM's Perhaps you will need yo transfer and clear the DM's every four hours. Also CQM1-CPU41 has 6K DM's. If you can spare a PC all the time, you may want to try the demo of either CX Supervisor or CX Server Lite. CX Server Lite Demo @ MrPLC.com CX Supervisor Demo @ MrPLC.com

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Thanks for the advice and the conformation of my logic Jay, for now I think I will be stuck with getting the data out every few hours until I can show people the data that can be collected, and then there might be some investment into better means. One thing I did not mention was the PLC is situated inside an AGV; each event is a position or button press along the route. The PLC is quite remote. I like the idea of the serial printer too guest_513 and I will look to that. But I also think that an industrial PC would be cool. Thanks again for your help Wayne Hollis

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A serial printer is very good idea, I think it will be the cheapest and the most effective solution. If PLC is remote, you may also consider wireless modems. With a wireless modem, you will be able to trace all your AGV's with an industrial PC, and with little modification on your PLC program and writing a PC program with the some components of OMRON, you may control your AGV with just a few mouse click. More than logging your data, you will be able to update, modify the software of AGV online, and you will be able to see the type of error in case of any failure. Imagine that you just select the target on the map of the plant with mouse click, then right click the AGV icon, then assign the target and AGV. Its just like a strategy game! Wayne, you are so lucky because you are playing with my toy of dreams. Consider wireless modem. Another subject: How you guide your AGV? Generally AGV s sense mettalic stripes under the ground level. 2 ~ 3 years ago, I had offered RFID to one of our customer for AGV. For the guidance of AGV, they buried metalic stripes under the ground, an with a metal sensor, AGV was able to find its way. Unfortunately, they had encountered some problems with sensors, and AGV falls in to error. I offered them to bury RFID Tags under the floor on important junction points. This will increase effectiveness of guidance. Best Regards

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it is fun to work with them somtimes but i will only be with them for a few more months, as i am an apprentice i will move into another department. we use magnetic tape ontop of the floor and a magnetic position sensor http://www.carlencontrols.com/macome.html that system is over 18 years old and we got it from a company called shinko electric (Nihon). i will be looking at new methods of guidence next month hopfully i will post some more information about our agv's if you like, pics and data sheets. don't laugh if they look home made though (they were)

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controling the agvs like a stratgy game would be cool.

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