Technical data

The communications start and end point of a logical channel between two
stations on the bus is known as a Service-Access Point (SAP). A SAP is a
further address criterion in addition to the station address. You must specify
a SAP number for each channel to be able to use layer 2 services.
3.2.2.1 Addressing Model for Explicit Communication
(for S5-S5, free layer 2 and FMA)
An interface to the user process is specified for SIMATIC S5 by the
interface number and job number.
In the CP itself, a job is identified and managed using only the job number
(Fig. 3.6).
The assignment of the job number to the SAP must be unique both (local
and remote). When configuring the CP 5430 TF/CP 5431 FMS, the
communication relations to other stations must be specified.
Process A
ANR
1 2 3
Process B
ANR
4 5 6
Process C
ANR
7 8 ...
Job numbers
all unique
01
2
3n
PLC
ANR
1,3
2
4, 5, 6
7, ...
8. ...
CP
SAP
11,13 22
34, 35, 36
47 48
L2 address 2
L2 bus
SSNR
Fig. 3.6 Addressing Model for Communication on the CP
Fundamentals of the Model B8976060/02
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