Module Diagnosis; Example Of A Slot Assignment; Structure Of The Device Identifier - Siemens Simatic 6ES7 157-0AD81-0 A0 Series Manual

Diagnostics Using the User Program
Device identifier
The device identifier is a code that uniquely identifies the DP slave (PROFIBUS ID
number).
Table 10-6 Structure of the device identifier
Byte 4
80
H
10.2.2

Module diagnosis

The module diagnosis identifies the IM 157 slots for which there is a diagnosis.
The terms slave, module and slot
A slave is a bus node that can be accessed via a separate PROFIBUS address. It
can physically or logically consist of one or more modules. The slaves and their
modules are depicted in the module diagnosis in virtual slots:
S A non-modular slave always occupies two slots.
The first slot represents a "virtual header module" and the second a "virtual
module".
S A modular slave that consists of x modules occupies x+1 slots.
The first slot is assigned to the header module; the remaining slots are
assigned in ascending order to the individual modules.

Example of a slot assignment

Link
PROFIBUS address
Slot
Figure 10-2 Example of a slot assignment
10-6
Byte 5
52 IM 157
H
3 4
1 2 3 4 5 6
1st slave 2nd slave
Designation
Underlying PROFIBUS
5 7
7 8 9 10 11 12
3rd slave 4th slave
DP/PA Link and Y Link Bus Couplings
A5E00193841-01 1