Siemens S7-300 - IO Controller Mode with S7-400; Multicomputing Mode - Assigning the CP to the CPU (STEP 7 V5.5); Programming

CP as PROFINET IO controller
6.3 IO controller mode with S7-400
Configuring and commissioning S7 CPs for Industrial Ethernet
Configuration Manual, 09/2013, C79000-G8976-C182-13
119
6.3
IO controller mode with S7-400
6.3.1
Multicomputing mode - assigning the CP to the CPU (STEP 7 V5.5)
If you use the CP in an S7 station with several CPUs (multicomputing) for PROFINET IO
operation, you must assign the CP to a CPU in the configuration.
Note
Note the following points:
•
CP slot in PROFINET IO mode
PROFINET IO operation is possible only with one CP located in the central rack.
•
CPU "startup" configuration when using the IE/PB Link PN IO
If you use the IE/PB Link PN IO as a PROFINET IO device, select the option:
"Startup when expected/actual config. differ" for the CPU in the "Startup" parameter
group.
Otherwise your system will not start up automatically after power up or following a power
outage.
6.3.2
Programming
No special program blocks are required for the basic functions of the PROFINET IO mode.
For acyclic communication with the PROFINET IO devices using data records and for
special additional functions, the following program blocks are available on the CPU:
Meaning
RDREC (SFB 52)
Read data record
WRREC (SFB 53)
Write data record
RALRM (SFB 54)
Receive alarm
RD_DPAR (SFB 81)
Read predefined parameters
GEO_LOG (SFC 70)
Identify the start address of a module
LOG_GEO (SFC 71)
Identify the slot belonging to a logical address
For a detailed description of these program blocks, refer to the "System Software for S7-
300/400 System and Standard Functions" manual /13/ (Page 231).
Assignment of an initial value with consistent PROFINET IO user data > 32 bytes
If you have consistent PROFINET IO user data areas > 32 bytes, the system does not
assign initial values. You should therefore set the initial value for all PROFINET IO user data
areas > 32 bytes using the corresponding error OBs.