Adding CRT message using the siemens S5 150 CPU

I am working with an S5 150 PLC used on a MAN Lithoman press.

I am trying to add a message to be displayed via a CRT monitor.

I have figured out and found the data block file in the KS format. But I can not figure out how to associate the new added message with a predefined address which trigger the message when the fault occurs.

If any one knows how to do this please respond?

Thanks