Hi Folks,

I have a problem in motion control with s7 1200.

I use some Technology objects using Cpu 1214. 

After Cpu restarts , Actual Position Value loads to zero.

How can I reload the previous Position Value ?

I tried MC_write function but it is not successful because this function does not work on "actual position" tag.

I think if I can find a way to use MC_Halt function just  before restarting, it will solve my problem, but it seams impossible.

But everytime when you restart the CPU, is it not necessary to do HOMING? Or you want to get that position to the Homing Position value?

Hi jay,

You are right, every time CPU restarts, for absolute move function and some other functions you need to perform homing and having "HOMED" bit ON.

My exact problem  is on power loss times, when axis was working and was not finished its task.

At this situation, after powering ON again,I want axis finish its incomplete job (I mean the rest part of its path) and then do " homing" to get ready for next absolute movement job.

But as soon as CPU power up, value of ActualPosition register cleared and I miss where axis was. 

Thank You Yuwen,

I will test it.