Assignment Of The Data Area - Siemens SIMATIC S5 Manual

3.4 Assignment of the Data Area

The three data blocks DB-A, DB-B and DB-C occupy space in the data area. Whereas, previously,
the data blocks DB-A, DB-B and DB-C, as well as the alternative data blocks DB-A' and DB-C' had
to have subsequent DB numbers, all data block numbers can now be allocated freely. In the
programmable controllers S5-115U, CPU 945, S5-135U and S5-155U the DB types (DB/DX) of the
individual data blocks can also differ from each other. In the following, however, we generally use
the term DB number.
When assigning parameters to the DB numbers (and DB types) you must differentiate between the
parameter assignment types of the function block FB 162:
Calling the FB 162 with direct parameter assignment:
The DB number for the data block DB-A is indicated at the block parameter DBNR. All the other
DB numbers have to be entered in the operating range of the function block in the data block DB-A.
Calling the FB 162 with indirect parameter assignment:
Before calling the FB 162 the data block DB-A must be selected. All DB numbers must be entered
in the operating range of the function block in the data block DB-A.
Data block DB-A contains the controller messages 0 to 12 and the messages 13 and 14 according
to the assignment in the previous function block FB 162 for the module 6ES5 244-3AA13.
Data block DB-B contains message 15 and the data read from the module (messages 16 to 25 and
46).
Data block DB-C contains the second sets of data for controllers 0 to 12 in messages 30 to 42.
If the self-tuning parameters are to be read from the module, this data can be stored in data blocks
DB-A and DB-C or in the next two blocks DB-A' and DB-C' as required.
The assignment in data blocks DB-A' and DB-C' is identical to that in DB-A and DB-C.
Exception: since messages 13 and 14 cannot be read from the temperature controller module,
they are not included in data block DB-A'. Data block DB-A' must only be set up as far as DW 223.
Further values which can be read from the module (actual values, manipulated variables, minimum
values, maximum values, cumulative setpoints and curve values of channel 13) are stored in data
block DB-B. This also contains messages 15, 16 and 46.
IP244
C79000–B8576–C861–02
Function
5–15