A new TQX board and two TN52NQ2 boards placed in OSN8800 (5.51.05.35) for service expansion. TQX placed in slot 36, two TN52NQ2 placed in slot 26 and slot 27. NQ2 which in slot 26 reported BUS_ERR after configuring ODU2 SNCP service between TQX and two NQ2.
TN52NQ2 board which is in slot 26 reported BUS_ERR alarm.
1 Checked alarm, 26-NQ2 reported BUS-ERR, the parameter is Para  =0x04, para  =0x5b, which means the problem caused from TQX->slaver XCS->26-NQ2.If Para  =0x03, it means the problem caused from TQX->master XCS->26-NQ2
2 Replaced the NQ2 board from slot27 to slot 26, the alarm still on. It means none business of NQ2 board.
3 Replaced the TQX board and configured SNCP service again, BUS-ERR appeared again. It means the TQX board is good.
4 Plug out the slave XCS board and replaced a new one, BUS-ERR disappeared
The cause of BUS_ERR which reported by NQ2.
1 The 26-NQ2 hardware failure.
2 The TQX board is failed.
3 The XCS board has some problem.
4 The slot26 or slot which place XCS board has some problem.
We should check parameters if BUS-ERR occurred. Identify the problem related with master XCS or slave XCS, and then we can use reconfiguration method or replacement method to solve problem.