Et200S+counter 24V 100khZ

Does anyone know how to load the "old" countervalue again in the actual coutervalue when an installation powers down, and up again?

I have programmed this but it does'nt work, programming error I think!
When a travel has been done and the counter is 500 mm.
When suddenly the power turns down and S7 starts up again it shows
the actual value is 0 mm (shown on a TP170A) but this must be the 500 mm instead

greatings Daevy

hello!
The counter does not have any memory when power is down.
Move the actual value to the loadvalue (or some memory place) and trigger the value when the plc starts up..

I know you're using S7, but the concept is the same. Since I don't have S7, here's an example using Rslogix.

How are you getting this count value? Can you use an absolute encoder to retain the value at all times. Otherwise you have to do as already suggested.

cheers

Can the device that is being positioned move after power down (because of the inertia) ?
And, if this is the case, will it be a problem for the application if the position is wrong by a magnitude similar to the movement after powerdown ?
If so, then the only solution is to reset the encoder by moving it to the home position when a power-up is detected.

Ok, thanks folks.

I seem to have solved the problem by placing the old value in a DB-word and reload it in OB100 into the counter again.
Would there be people also have problems with it, I'can mail them an example program.

Thanks for the replies, but 3 hours of surching for a solution did it.