Siemens sinumerik 840D sl Function Manual page 191

Detailed description
2.3 SINUMERIK 840Di with PROFIBUS DP
Conditions and recommendations for MD10062
MD10062 $MN_POSCTRL_CYCLE_DELAY (position control cycle offset)
The position controller cycle offset (T
fulfilled within a PROFIBUS-DP/system cycle:
• Cyclic communication with the DP slaves (drives) must be completed before the position
• The position controller must have finished before the PROFIBUS-DP/system cycle comes
The following setting is recommended as approximate value for the position control cycle
offset:
T
M
• T
• Tmax
Note
HMI Advanced
The maximum position-controller time is displayed in the NC Load dialog box under Menu
Area Switchover > Diagnostics > Service Displays > System Resources.
Error response
• Interrupt: "380005 PROFIBUS DP: Bus access conflict, type t, counter z"
Cause of errors/error handling
• t = 1
• t = 2
14
controller is started.
Condition: T > T
M DX
to an end.
Condition: T + T < T
M Lag
= T - 3*Tmax
DP position controller
DP
Position-control cycle or PROFIBUS-DP cycle
position controller
The position-control cycle offset selected is too small. Cyclic PROFIBUS-DP
communication with the drives was not completed before the position controller started.
Increase the position-control cycle offset.
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.
– 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.
) must be set such that the following conditions are
M
DP
Special functions: Cycle Times (G3)
Function Manual, 11/2006, 6FC5397-2BP10-2BA0