Nortel Meridian Meridian 1 Upgrade Manual page 272

Page 272 of 284
NN43021-469 Standard 01.01 May 2007
Appendix A: Upgrade checklists
Note: A DIGS Card is located in the card slot position for IGS 1 in all
network shelves. The IGS 1 slot detects the clock signals from the active
clock controller and distributes the clock to the entire group. Three out of
four IGS cards can be disabled at any given time via LD 39, the IGS 1
that is associated with the active clock cannot be disabled via software,
e.g. if clock 1 is active then IGS's 3,7,11,15 and 19 can never be disabled
as they are providing clock for their respective network groups.