Technical data

SINAUT TD7 software package for the CPU
2.8 SFC / SFB system blocks used
Software
System Manual, 07/2009, C79000-G8976-C222-07
327
Len
Min_Xcom
=Len
ComBuffer
+ Offset + Len
dt
+ (Len
ComBuffer
/ Len
MinTgrm
+ 1) * Len
Separator
= 76 + 40 + 4 + (76 / 14 + 1) * 2
= 120 + 12 = 132 bytes minimum
a) For B communication:
Len
Min_Bcom
=Len
ComBuffer
+ Offset + Len
dt
+ (Len
ComBuffer
/ Len
MinTgrm
+ 1) * Len
Separator
= 202 + 40 + 4 + (202 / 14 + 1) * 2
= 236 + 40 = 276 bytes minimum
If FC TestCopy determines that the DB TestCopyData is not long enough, an error message
to this effect is entered in data byte DBB28.
2.8 SFC / SFB system blocks used
Introduction
System functions, SFCs, and system function blocks, SFBs, are part of the operating system
of the CPUs and are used by the TD7 blocks as auxiliary blocks. Since it should be possible
to run the TD7 package on all CPU types, as a basic rule the only system blocks used are
those that are available on all CPU types. Here, it is mainly the 300 CPUs that determine the
system blocks that can be used. Presently there are only a few exceptions to this rule,
namely, FC ListGenerator which has separate versions for S7-300 and S7-400 and FB
BCom which is only used for S7-400 because communication function block connections are
only possible there.
Because the system blocks are part of the operating system, they use no user memory.
Below, you will see an overview of the system blocks used that exist on all CPU types.
SFC 0 SET_CLK
Block for setting the date and time of day in the CPU.
SFC 1 READ_CLK
Block for reading the date and time of day on the CPU.
SFC 20 BLKMOV
Block for copying contiguous data areas.
SFC 22 CREATE_DB
Block for online generation of data blocks.
SFC 46 STP