[?]: STEP 5 problem with EPROM

[dekor]

Dear friends,
I have a PLC S5 115 CPU 943 connected to an operator panel LAUER.
I make a program . Is working OK.
I write this program on EPROM.
I delete the existing program on CPU, Then I insert the EPROM.
I switch on the CPU.
The program looks like is working,( CPU is on RUN status) but there is no communication between CPU and OP.

Can you explain me were is the mistake?

Thanks,
dekor