Appendix   
A.1 Information about upgrading to a CPU 31xC or CPU 31x 
  CPU 31xC and CPU 31x, Technical Data 
A-2  Manual, 01/2006 Edition, A5E00105475-06 
... then please note if you upgrade to one of the following CPUs  
 
As of version CPU  Order number 
Firmware  Hardware 
Hereafter called 
312  6ES7312-1AD10-0AB0  V2.0.0  01 
312C  6ES7312-5BD01-0AB0  V2.0.0  01 
313C  6ES7313-5BE01-0AB0  V2.0.0  01 
313C-2 PtP  6ES7313-6BE01-0AB0  V2.0.0  01 
313C-2 DP  6ES7313-6CE01-0AB0  V2.0.0  01 
314  6ES7314-1AF10-0AB0  V2.0.0  01 
314C-2 PtP  6ES7314-6BF01-0AB0  V2.0.0  01 
314C-2 DP  6ES7314-6CF01-0AB0  V2.0.0  01 
315-2 DP  6ES7315-2AG10-0AB0  V2.0.0  01 
315-2 PN/DP  6ES7315-2EG10-0AB0  V2.3.0  01 
 317-2 DP  6ES7317-2AJ10-0AB0  V2.1.0  01 
317-2 PN/DP  6ES7317-2EJ10-0AB0  V2.3.0  01 
319-3 PN/DP  6ES7318-3EL00-0AB0  V2.4.0  01 
CPU 31xC/31x 
Reference 
If you intend to migrate from PROFIBUS DP to PROFINET, we also recommend the 
following manual: 
Programming manual From PROFIBUS DP to PROFINET IO
 
See also 
DPV1 (Page 3-33) 
A.1.2  Changed behavior of certain SFCs 
SFC 56, SFC 57 and SFC 13 which work asynchronously 
Some of the SFCs that work asynchronously, when used on CPUs 312IFM – 318-2 DP, were 
always, or under certain conditions, processed after the first call ("quasi-synchronous"). 
On the 31xC/31x CPUs these SFCs actually run asynchronously. Asynchronous processing 
may cover multiple OB1 cycles. As a result, a wait loop may turn into an endless loop within 
an OB. 
The following SFCs are affected: 
•  SFC 56 "WR_DPARM"; SFC 57 "PARM_MOD" 
On CPUs 312 IFM to 318-2 DP, these SFCs always work "quasi-synchronously" during 
communication with centralized I/O modules and always work synchronously during 
communication with distributed I/O modules.