HI,ALL
I have a problem. A S7 400 syetem, CPU 414 ,no battery ,alerm light on,install the battery, alerm disappear,but when I cut the power of CPU,the data in datablock also disappear,why???
I can't understand,help!
HI THERE
either whole program will go
or nothing
so just re check your problem
may be you have downloaded the data block because me which old data might have got disappeared
do you use the blue lithium batteries? if so smash this thing on some table a couple of times. they build up an oxyd layer that prevents enough current to flow for keeping the data. you could also shortcut it with a 100ohm resistor but smashing the battery does the job also. its a problem with this batteries since over 10 years. if you search long enough you will find some trouble information @ the siemens support on this topic