Hello everyone, I'm new to SIMATC STEP7 environment, I've created a small project with S7-400 hardware interface with profibus slave device, it doesn't show any error while compiling but showing error message when downloaded into hardware. Diagnostic buffer message can be found in the attachment it shows

I/O access error when updating the process image input table

P area, double-word access, access address:      0

process image partition no.:  0

not user relevant(Z1): 2942

Requested OB: Program execution error OB (OB85)

OB not found, or disabled, or cannot be started in the in the current operating mode

External error, Incoming event.

Can anyone help me with this issue? Thank in advance

It means that the input with address 0 which is readout as a double-word give no answer when there is asked for...

In OB122 you could also see without a STOP of the CPU where the address is called.