Siemens SINUMERIK 840D sl Function Manual page 189

• Cyclic communication with the DP slaves (drives) must be completed before the position
controller is started.
Condition: T
• The position controller must have finished before the PROFIBUS-DP/system cycle comes
to an end.
Condition: T
The following setting is recommended as approximate value for the position control cycle
offset:
T = T
M
T : Position-control cycle or PROFIBUS-DP cycle
DP
Tmax
Note
HMI Advanced
The position controller maximum time is displayed in the "NC load" dialog under "Menu range
switchover" > "Diagnosis" > "Service displays" > "System resources".
Error response
Alarm 380005 "PROFIBUS-DP: Bus access conflict, type t, counter z"
Causes of error/error handling:
• t = 1
The position-control cycle offset selected is too small. Cyclic PROFIBUS-DP
communication with the drives was not completed before the position controller started.
Remedy: Increase the position-control cycle offset.
• t = 2
The position-control cycle offset selected is too large. Cyclic PROFIBUS-DP
communication with the drives started before the position controller had finished. The
position controller requires more computation time than is available in the PROFIBUS-DP
cycle.
Remedy:
-
-
Special Functions
Function Manual, 09/2011, 6FC5397-2BP40-2BA0
> T
M DX
+ T < T
M Lag DP
- 3*Tmax
DP position controller
: Position controller maximum time
position controller
Decrease the position-control cycle offset
or
Increase the PROFIBUS-DP cycle.
The PROFIBUS-DP cycle must be set in the SIMATIC S7 project in advance.
3.4 SINUMERIK 840Di with PROFIBUS DP
G3: Cycle times
189