6 Configuring and Programming the CP as a PROFINET IO Device
Data consistency
The length information in the block call must be identical to the total length of the input or output data configured for this PROFINET IO device.
The entire input or output data area of the PROFINET IO controller is transferred in its entirety between the CP and CPU and is therefore consistent.
Note: Remember, however, that in terms of the “IO user data” within a PROFINET IO system, only the data consistency of individual IO slots can be guaranteed. This applies regardless of whether consistent data transfer between the CPU and CP is guaranteed for the blocks described here.
6.4.2Initialization and Configuration
Initialization
As a PROFINET IO device, the CP requires the following information in the user program for configuration by the PROFINET IO controller at every startup:
SLength of the input data (when FC11 is called)
SLength of the output data (when FC12 is called)
When the connection is established between the PROFINET IO controller and the PROFINET IO devices of a PROFINET IO line, the entire length of the input and output data is checked. The PROFINET IO controller compares the configured entire length of the input and output data with the LEN parameter of FC11 and FC12 in the user program of the device for every PROFINET IO device.
If the length information for the input and output data does not match, the block is terminated with an error.
During this initialization phase, the two blocks must be called until FC11 signals DONE=1 and FC12 signals NDR=1.
Notice
Remember that the successful configuration by the PROFINET IO controller is only possible after local initialization by the FC calls PN IO_SEND (FC11) for the input data and PN IO_RECV (FC12) for the output data.
Note
During initialization, the data of PNIO_SEND (FC11) is not evaluated and the data of PNIO_RECV (FC12) is initialized with default values.
FC11 and FC12 transfer valid data only following the subsequent calls.
B3L−28 | CP |
Release 03/2007 |
