General Information On Program Processing - Siemens SIMATIC CP 340 User Manual

Communication using function blocks

6.7 General Information on Program Processing

6.7 General Information on Program Processing
Start-up Behavior of CP 340 Programmable Controller
The parameterization data are generated using CP 340: Point-to-Point Communication,
Parameter Assignment parameterization interface and transmitted to the CPU with the STEP
7 software. Each time the CPU is started up, the current parameters are transferred to the
CP 340 by the system service of the CPU.
Start-up Behavior: FB-CP 340
Once the connection between the CPU and the CP 340 has been established, the CP 340
must be initialized.
For each function block, P_SEND, P_RCV, P_PRINT, there is a separate start-up
coordination. Before requests can be actively processed, the accompanying start-up
procedure must be completed.
Disable interrupts
The interrupts are not disabled in the function blocks.
Interrupt behavior
The CP 340 module can trigger a diagnostics interrupt in the CPU. When this happens, the
operating system provides the user with 4 bytes of interupt information. Interpretation of the
interrupt information must be programmed by the user (OB 82).
The CP 340 function blocks cannot be called in the process or diagnostics interrupt program.
Addressing the module
The logical basic address is defined via STEP 7 and must be specified by the user under the
block parameter LADDR.
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PtP coupling and configuration of CP 340
Manual, 04/2011, A5E00369892-03