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AMP(H)41_MANUAL-en_R11 - 2019-03-28
Absolute Encoder AMP(H) 41
11.2
Use of the PROFIBUS diagnosis
In a PROFIBUS system, the PROFIBUS masters provide the so-called host system, e.g. a
PLC-CPU, with process data. If there is no slave on the bus or it is no longer accessible, or the
slave reports a fault itself, the master must notify the host system of the fault in one form or
another. There are several possibilities here, whose evaluation is solely decided by the
application in the host system.
Generally a host system is not stopped by the failure of just one component on the bus, but
must react to the failure in an appropriate way in accordance with the safety regulations.
Normally the master firstly provides the host system with a summary diagnosis, which the host
system reads cyclically from the master, and through which the user is informed of the state of
the individual clients on the bus. If a client is reported defective in the summary diagnosis, the
host can request further data from the master (slave diagnosis), which then allows a detailed
evaluation of the reasons for the fault. The reports obtained in this way can be generated from
the master if the affected slave fails to respond to the master's requests, or they may come
directly from the slave if it reports a fault itself. The generation or reading of a diagnosis report
between the master and slave takes place automatically and does not need to be programmed
by the user.
In addition to the standard diagnosis information, the measuring system provides an extended
diagnosis report with module status information.
11.2.1
Standard diagnosis
The DP standard diagnosis is structured as follows. The perspective is always as viewed from
the master to the slave.
Byte no.
Meaning
Standard
diagnosis
Byte 1
Station status 1
General part
Byte 2
Station status 2
Byte 3
Station status 3
Byte 4
Master address
Byte 5
Manufacturer’s identifier HI byte
Byte 6
Manufacturer’s identifier LO byte
Extended
diagnosis
Byte 7
Length (in bytes) of the extended
diagnosis including this byte
Device-specific
extensions
Byte 8
to
Byte 241 (max)
Further device-specific diagnosis
Summary of Contents for AMP 41
Page 96: ...96 AMP H 41_MANUAL en_R11 2019 03 28 Absolute Encoder AMP H 41 16 3 T V certificate...
Page 97: ...Absolute Encoder AMP H 41 AMP H 41_MANUAL en_R11 2019 03 28 97 16 4 PROFIBUS DP certificate...
Page 98: ...98 AMP H 41_MANUAL en_R11 2019 03 28 Absolute Encoder AMP H 41 16 5 PROFIsafe certificate...
