[?]: Diagnostic Repeater

[sonu]

I have a system using a S7-315DP.
I have purchased a Diagnostic Repeater and placed in the network to try and gain insight to problems we have with the network.
I am having problems with using the repeater.
I cannot seem to get a network topology from the unit.
I am using Step7 V5.4 , but the Prepare Line Diagnostics button remains grayed out.
When I go show network topology, i don't get the topology with lengths.
I am really confused.
If someone has had experience with this please help.

[sania]

you need be connected to PB
your pc/pg need be inserted into s7project
connectinon interface assign to your PB
go online with hardware
check PB
plc-> profibus -> prepare line diagnostics