OSN3500 SSN1SXCSA single board needs to be inserted in the corresponding slot of the subrack according to the requirements, otherwise the single board can not work properly.SXCSA single board can be inserted in the slot 9, slot 10 of the subrack.Default slot 9 is the main board slot, slot 10 is the backup board slot. After installing the crossover, please remember to close the SXCSA veneer puller bar wrench to the main, with the crossover board wrench in the unclosed such as the insertion of the backup crossover board, resulting in a half-minute business interruption of tens of seconds. When inserting a new cross board in the open service sub-frame, please note that the current cross board's puller bar wrench is in a closed state.