PC Control / Profi Control 645-12M Instruction Manual pdf - Kuhnke

PROFIBUS Operands messages
4.5.3. PROFIBUS messages
Apart from updating the PROFIBUS process image, the ALI
of PC Control 645-12M has a management functionality
for specifc operand ranges that indicate the status of the DP
master machine, ALI and the connections to the slaves.
These are
Status of PROFIBUS master:
Slave status messages:
Connection status:
PFxx.yy
PSaxx.yy
PEaxx.yy
The contents and significance of the operand ranges differ
from the operands of the same name in Kuhnke controllers
with transfer rates up to 500 kbit/s.
If external operands are linked in a program (e.g. inputs of
a Profi I/O 690E), it has to be taken special care of their
validity. If, for example, the bus connection is interrupted
the received value may no longer correspond to the real
status of the input. In order to avoid wrong switching operations
as a result we urgently recommend to carefully
analyse the above-mentioned PROFIBUS messages in the
program.
For startup and testing, we recommend that you use
KUBES' "Display single address" and "Display address
range" options to make these messages visible.
4 - 22