Siemens SIMATIC CP 440 Manual page 109

Example 2
The symbol name of the data block used, DB 20, is "CP_DB"; the symbol name for
the send DB number is "SEND_DBNO" and is located in data block DB 20 in the
data word DBW 0.
The start address of the send frame is "SEND_DWNO" and is located in the data
block DB 20 in DBW 2. The frame length is "SEND_LEN" and is located in the data
block DB 20 in DBW 4.
The variable used for the module address is the memory word "BGADR" (MW21),
for the DONE parameter the memory marker "SEND_DONE" (M26.0), for the
ERROR parameter the memory marker "SEND_ERROR" (M26.1), and for the
STATUS parameter the memory word "SEND_STATUS" (MW27).
The STL listings for the example are shown on the following page.
Example of an "Absolutely Addressed Actual Parameter"
Call of the FB 10 with absolutely addressed actual parameters:
STL
Network 1:
CALL FB 10, DB10
REQ := M 0.6
R := M 5.0
LADDR := MW21
DB_NO := DB20.DBW0
DBB_NO := DB20.DBW2
LEN := DB20.DBW4
DONE := M 26.0
ERROR := M 26.1
STATUS := MW 27
Point-to-point connection CP 440 Installation and Parameter Assignment
A5E00057742-02
Communication Using Function Blocks
Explanation
//SEND initiation
//RESET initiation
//Basic address in MW21
//DB no. in DBW0 of DB20
//From DBB no., located in DBW2 of DB20
//Length located in DBW4 of DB20
//Terminated without errors
//Terminated with errors
//Status word
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