General Information On Program Processing - Siemens SIMATIC S7-400 Equipment Manual

Communication via Function Blocks

6.5 General Information on Program Processing

STL
EN/ENO Mechanism
The parameters EN and ENO are only present in the graphical representation (LAD or FBD). The
block is started with EN = TRUE. If the function is completed without errors, ENO = TRUE is set.
To process these parameters, the compiler uses the binary result (BR).
The binary result is set to the signal state "1" if the block was terminated without errors. If there
was an error, the binary result is set to "0".
6.5 General Information on Program Processing
Startup Characteristics of the CP 440 Programmable Logic Controller
The configuration data is created with the aid of the CP 440: Point-to-Point Communication,
Parameter Assignment parameter assignment and transferred to the CPU with the STEP 7
software. Each time the CPU is started up, the current parameters are transferred to the CP 440
by the system service of the CPU.
Startup Characteristics, FB-CP 440
Once the connection between the CPU and the CP 440 has been established, the CP 440 must
be initialized.
For each function block (SEND_440, RECV_440, RES_RECV) there is a separate startup
coordination. Before requests can be actively processed, the accompanying startup procedure
must be completed.
Disabling alarms
In the function blocks the interrupts are not disabled.
88
FB 10, DB10
REQ := SEND_REQ
R := SEND_R
LADDR := BGADR
DB_NO := CP_DB.SEND_DBNR
DBB_NO := CP_DB.SEND_DWNR
LEN := CP_DB.SEND_LAE
DONE := SEND_DONE
ERROR := SEND_ERROR
STATUS := SEND_STATUS
Point-to-point connection CP 440 Installation and Parameter Assignment
//Activates SEND
//Activates RESET
//Basic address
//Send DB no.
//Message frame as of data
word
//Message frame length
//Terminated without error
//Terminated with error
//Status word
Equipment Manual, 03/2022, A5E00057742-AE