STEP5 TO STEP7 CONVERTION

Hi chinna

this form of direct memory access is no longer possible in S7 which means you can not directly convert this S5 program to S7.

Way forward is to understand what the S5 program is doing and then implement it as new logic in S7.

As each S5 CPU has its own memory allocation, first thing to do is grab the manual for the S5 CPU that this program belongs to and determine what memory area starts at absolute address E400hex (e.g. S Flags start addresses if this is a 928B CPU).

Thereafter, work out what the content of the various Flagwords that are used for the index values are or can be (e.g. FY 252, FY254 etc.) and then work out the functionality of the S5 program from there.

Ultimately, your S5 program will do a transfer of some Bytes from one memory area to another (which is what the TNB 0 does at the end) and your corresponding S7 program could be a simple as the call of a Blockmove (or a bit more complex if the index values for the source and destination are variable).

A search in this Forum and/or Siemens support webpage for LIR & TNB will also yield additional hopefully helpful info.