how many times can you write to a plc/hmi

I have read that there is a maximum of ten thousand writes to an eprom within a plc or an hmi.

I have had a plc and hmi on my desk for over 2 years which I use for program testing and experimenting with.
I would say that I have written to them several thousand times.

Am I on the wrong thread and confusing eeproms with eproms because this plc and hmi might have to go on a machine one day.

No, you are not wrong. There is a limited number of Write Cycles for EEPROMs, especially the older technology ones. A higher Voltage is used to Write to them, which causes a small amount of damage each time.

The newer EEPROM and Flash Memory is good for 1,000,000 Cycles or more, and the technology is always improving.

I haven't worried to much about it on our production machines, because we don't make changes that often. However, in your specific case, it may become a problem with all the Writes that you do.

Stu.....

But it is always a good idea to rotate test machines if you intend to put them to work at some point.
Your test machine is likely very well "broke in" but also out of warranty and maybe at an old revision level or is that kept up-to-date?

Right, thank you.

Time for me to rotate methinks

We have the same plc and hmi in several of our machines (misubishi plc's and beijer hmi's)

They are all the same revision level as they have never been touched. Some will have only been written to once.

I am glad I asked this question


Thanks again


Ronnie