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quarter20

Melsec Fx-1n 60 plc memory loss issues

8 posts in this topic

I have several Mitsubishi Melsec Fx-1n 60 plc's that sometimes go for weeks without the equipment getting powered up when not in use. I know that it has the eeprom memory- does anyone know of a cheap effective hack to attach a battery or other device to the plc to retain the memory? I thought of attaching a battery backup unit from staples to it-any thoughts? The program operates ink pad printers which has several "jobs" in memory- (with parameter settings) it loses. This is leading to excessive set-up time when production is required. Any help is greatly appreciated!

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Not sure if you are aware, there is a FX1N-BAT available from Mitsubishi which installs into the front of the PLC to provide memory data retention for the PLC data. Easy to install. The volatile ram in the PLC is good for about 2 weeks as a rule as the backup up power is only supplied via an on board capacitor, very limit resource. Hope that helps

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Thanks Colandra! I will be checking that out at this time. Necessity is the father of innovation...they say?

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Dear Quarter20, Did you use the right retentive registers to store your data in? There are EEPROM buffered words and Capacitor buffered words. The battery suggestion from Colandra is also a good option to keep your data in the memory. To keep it cheap, just leave the power on but that is probably too simple... Best regards, Theo V.

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My problem is that the memory for the different set-up recipes is being stored in the plc. It stays there as long as the machine remains under power, but unfortunately-they are used periodically and may run for a few days and then sit unplugged for several weeks. The manufacturer of the machine did some programming "upgrades" that cost our firm$$ heavily as we shipped the equipment to them and back. While they were there, they should have recommended the battery upgrade while they were doing the service on them, but they did not. After we lost everything (memory) during transit, and before actual use, they said they were not even aware of the battery problem.??and didn't really know what to recommend. That is what sparked my research on the dilemma. We ended up buying the correct spec'd battery for the plc processor @ $100 each and it seems to have solved the problem, although they are only available in limited quantity for now so there is some waiting involved to get all of our units implemented with the fix. Now I am getting more familiar with the Mitsubishi products and software so that future improvements can be examined in the functionality of the equipment. Thanks for everyone's support and assistance here at Mr. PLC!

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If you have the software GX Developer or GX developer FX ( cheapest for your model of PLC) you can upload all the data without the plc program and save it as a different file for each machine. Should you lose the values, it's 2 minutes work downloading the saved data back into the plc.

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FX1N will never lose the program, only the data values. FX1N uses EEPROM for the program. The FX1N-BAT is the correct solution for your current PLC. But please keep in mind FX1N is an obsolete platform. While I expect the battery will continue to be available for a while, I would strongly recommend upgrading it to an FX3G. Using the programming software, it's as easy as selecting 'Change PLC Type' to switch it over. And the terminals blocks are the same, so no wiring changes will be required for most applications.

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Absolutely the battery is the correct option - mine was more of a 'belt and braces' method in the event of future battery failures.

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