STEP7 CPU 315-2 DP ISSUE

dear sir

I hope that you help me with the following fault message when i did hard ware

diagonistec check for the S7 cpu using on line connection AS, there is a ( bus fault

indication lamp flashing )for along period in my factory also(SF) fault lamp illuminate for

along period and the HMI on the profibus network has power but no any data or

program on it

AFTER CHECK the message was

DP slave not accessible by means of the bus

and by the check i found the status of the DP slave was:

module configured but not avialable, preset / acutal mis match (inserted and configured module type are not the same)

but over all the main program for machine still functioning and the machine in service

hoping for your response

thanks and best regards