Profibus-DP: bus %3 access conflict, type %1, counter %2


%1 = Conflict type

%2 = Serial number within a conflict sequence

%3 = Number of the affected bus


An access conflict occurred on the PROFIBUS DP in cyclic mode: The NCK attempted to write data to the bus or to read from the bus while cyclic data transfer was active. This can lead to data integrity problems.

Type 1: Cyclic transfer has not finished on the PROFIBUS when the NCK attempts to read data.



Type 2: The NCK has not finished writing data when cyclic transfer begins again. Counter %2 contains a serial number starting at 1. A maximum of 10 alarms are output in succession. If no conflicts occur in a DP cycle, the counter is reset and new alarms are output again on the next conflict.

- Alarm display.

Check the timing again, in particular ensure that the settings in

SYSCLOCK CYCLE TIME and POSCTRL CYCLE DELAY are correct: POSCTRL_CYCLE_DELAY must be larger for type 1. POSCTRL_CYCLE_DELAY must be smaller for type 2.

If alarm-free operation cannot be achieved with any POSCTRL CYCLE DELAY setting, SYSCLOCK_CYCLE_TIME must be increased.

Program Continuation:

If the error cannot be eliminated by this procedure, please make a note of the error text and contact the control system manufacturer.

Clear alarm with the Delete key or NC START.

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