Description
2.1 Block specification
FC 45
2-4
Function manual, Release 03/2006 , J31069-D0167-U001-A2-7618
Calculating MOBY data throughput
The formulas in the MOBY manual for configuration, mounting and service (Chapter 3) can
be used to calculate data throughput with the FC 45.
Configuration manuals are currently available for MOBY I (6GT2 097-4BA00-0EA2),
MOBY E (6GT2 397-4BA00-0EA2), MOBY F (6GT2 497-4BA00-0EA2), MOBY U
(6GT2 597-4BA00-0EA2) and MOBY D (6GT2 697-4BA00-0EA2).
Applicable in general:
t
k
Communication time between ASM, write/read device
and MDS
n
Amount of user data
k
Constants (see table in configuration manual)
k
bytes
t k t n
= + ⋅
t
bytes
Transmission time for 1 byte (see table in
configuration manual)
Transmission of the data to the MDS and transmission of the data between ASM and FC 45
take place in parallel. Usually no further time must be added for data transmission between
ASM and FC 45 so that the time t
k
calculated above represents the total duration of the
command.
However, commands may require more time under the following conditions.
•
A very large number of MOBY channels are processed in parallel.
•
Very few (or only one) system resources are available for non-cyclic telegrams.
•
Slow transmission speeds are used on PROFIBUS.
•
Other applications are running on the S7 which require the non-cyclic telegram services
(SFC 58/59) of the SIMATIC very frequently.