Siemens MOBY FC 56 Technical Description page 147

B.7 PROFIBUS Implementation
PROFIBUS is implemented on the MOBY-ASM strictly in accordance with the
standard IEC 61784-1:2002 Ed1 CP 3/1. Cyclic data communication (standard
specified by EN 50170) and optional non-cyclic data communication are used.
The following figure shows the communication interface to a MOBY-ASM. PAW
and PEW are exchanged cyclically between ASM and function block. PEW tells
the function block when commands and data may be transferred to the ASM.
Commands and data are put into data records.
Interface to the user
ASM_address
ASM_channel
MDS_IO_control
ECC_mode
MOBY_mode
scanning_time
Com-
mands
Data
acknow-
ledgments
x = Channel
n = No. of the command on ASM (n
* = SIMATIC S7 uses SAP 51 and SAP 54 for non-cyclic communication.
FC 56
J31069-D0155-U001-A0-7618
Programming MOBY-ASM on PROFIBUS-DP-V1
PAWx
PEWx
DR10x
Function
block
Parameter
DR11x
= number of buffers on ASM (see chap. 2.4)
max
Bus
SAP57
PAWx
SAP56
PEWx
SAP51*
DR10x(0)
SAP51*
DR11x(n)
Data
DR11x(1)
DR11x(0)
MOBY-ASM
ASM 475
Sequence
control
MOBY
MDS
driver
data
B-25