System Operation description Appendix KWinLink™ 1000 User Manual Release 1.9 K-16Figure K-13: Secondary Link operating after the switch back to PrimarySystem Operation descriptionNormal operation• TDM services are carried by the primary link• The secondary link (equipment and air interface) is operating but not carrying user traffic• TDM ports on the secondary IDUs are tri-stateSwitching to backup• Switching to secondary will occur in the following cases:• Loss of the primary air interface due to sync loss• Loss of the primary air interface due to failure of the receiver to acquire expectedTDM data during a period of 24ms• Primary equipment power off (either ODU or IDU, local or remote)• The switching result would be:• TDM ports on the primary IDUs turn to tri-state• TDM ports on the secondary IDUs become activeBackup operation • TDM services are carried by the secondary linkSwitching back toprimary• Switching back to primary will occur as soon as the Primary link is fully functional for 1second
