Norstar Service Cartridge (Clock Card) for Modular ICS.
This service cartridge uses slot "B" in the Norstar Modular ICS unit. It provides the clocking service that is required for digital networks. It is required if you are using DTI cartridges or ISDN-BRI Interface cartridges.
The Services Cartridge supports all clocking that is needed on the Norstar system, regardless of the quantity or mixture of DTIs or ISDN-BRI cartridges.
This cartridge cannot be used if a Copper Expansion Upgrade Cartridge is installed.
This unit is only compatible with the Modular ICS KSU unit.