Performance Data
B2–9
CP 343-5 for PROFIBUS / Manual Part B2
Release 11/2002
C79000-G8976-C160-02
Performance Data
4.1
Supported Transmission Rates
The transmission rate is set with the SIMATIC STEP 7 configuration software. For
permitted values, see Table 6-1 in Section 6.
4.2
Characteristics of FMS Connections
The following data are important for operating FMS connections:
Table 4-1
Component
Explanation / Values
Number of FMS connections
Maximum of 16
User data length
237 bytes for READ
233 bytes for WRITE and REPORT
Configurable variables
256 server variables and 256 variable descriptions
that can be loaded from the partner. These can be
distributed as required on the maximum number of
configurable FMS connections. The value applies
to elementary data types or arrays of elementary
data types.
This value does not apply to complex data types
(STRUCT)! Note the information in the manual /2/
about using complex data types (STRUCT).
Cycle Load Caused by FMS Connections
When calculating the reaction times with FMS connections, the run time of the
function blocks (FBs) in the S7-300 CPU (314-1 see Table 4-2 ) is the decisive
factor.
The table below shows the cycle load resulting from the available FCs in ms. The
values were obtained using a data length of 230 bytes (array).
Table 4-2
Component /
FB
FB
Number
Job Trigger in ms
(first call)
Job Active in ms
(next call)
Job Complete without
Errors in ms (last call)
IDENT
FB 2
1.8
0.2
5.5
READ
FB 3
2.2
0.2
7.6
4
