VIPA CPU 21 Series, Руководство пользователя, Страница: 206 / 394

Chapter 7 Deployment of the CPU 21xDP Manual VIPA CPU 21x
7-14 HB103E - Rev. 05/45
The various diagnostic functions of Profibus-DP allow a fast error detection
and localization. The diagnostic messages are transferred via the bus and
collected at the master.
The CPU 21xDP is sending diagnostic data at request from the master or
in case of an error. The diagnostic data consists of:
•
Norm diagnostic data (Byte0...5),
•
Device-related diagnostic data (Byte6...10)
•
User-specific diagnostic data (Byte11...15)
Via diag you define the start address, from where on the 6Byte user-
specific diagnostic data shall be stored in the CPU.
You may initiate and influence diagnostics by controlled access to this
area.
Note!
More detailed information about the structure and the control possibilities
on diagnostic messages are to find under "Diagnostic functions".
The recent state of the Profibus communication is readable from a 2Byte
status area in the periphery address area of the CPU, starting from the
status address.
Note!
More detailed information about the structure of a status message is to find
under "Status message internal to CPU".
Via this parameter you assign a Profibus address to your Profibus system.
As soon as you assign the length 0, the according data don't occupy any
memory space in the CPU.
You may also release CPU memory space by assigning the address range
limit (255 resp. 1023 for CPU firmware versions > 2.2.0) to the parameters
prn , diag and stat .
diag. adr.
stat. adr.
Profibus DP
address
Release CPU
areas