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7.6
The PROFIBUS module offers the possibility of sending diagnose telegrams. The
diagnose mechanism of the PROFIBUS-DP consists of two steps: First, the slave
signalizes to the master, that there are new diagnose data. Being the slave, it can
never start communication; it will, in a standard data exchange, respond by a
telegram of high priority, though. Then, the master will send a diagnose request to
the slave, which will, in return, transmit the present diagnose data.
From the user's point of view, the diagnose process is structured as follows:
7.6.1
From the user's point of view, the process is structured as follows:
Fig. 10: Structuring of the registers for user diagnose data
Jetter AG
Diagnose
Registers for Diagnose Data
Register 1m139:
Check, whether carrying out a diagnose command has
been completed, i.e. whether the diagnose telegram sent
last has been fetched by the master. The register value
must be 0 then. Only then, a new diagnose telegram can
be created. This is to make sure that diagnose information
does not get lost.
To interrupt the transmission of a diagnose telegram, issue
command 10 (see section 6.3.2 "Commands for
Transmitting Diagnose Data").
Register 1m140:
Enter the length of the diagnose data in byte. The length
must amount to between 10 and 32 bytes.
•
Only the standard diagnose data are transmitted according
to the PROFIBUS specification.
•
Additional transfer of user diagnose data
(e.g. if diagnose data of 4 bytes are to be transmitted to the
master, length = 14 must be written into the register).
Register 1m146:
From this register onwards, the diagnose data can be
entered in word mode now, the LowByte being placed on
the lower address.
Register 1m210:
From this register onwards, the above registers can also be
accessed in byte mode, the LowByte being placed on the
lower address.
Register 1m141 to
These registers are already occupied with the standard
1m145 (resp.
diagnose data and must not be changed.
1m200 to 1m209):
Byte Access
231
230
Word Access
156
Length = 10 bytes:
Length = (10 + number of user bytes) bytes:
219
218
217
216
150
149
JetWeb
215
214
213
212
211
148
147
146
210
49
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