Motorola 68230 - Vanguard 300 DSU/CSU Operator's Manual page 72

Adding or Replacing an ISDN Daughtercard
Introduction
The ISDN daughtercard provides an RJ45 connector on Port 1 and comes
installed from the factory if you ordered the ISDN option when you ordered your
Vanguard 300/305.
Packaging
The following items will be enclosed in the Vanguard ISDN daughtercard
package:
1 - Vanguard Daughtercard Installation Instructions
1 - Vanguard Daughtercard
1 - RJ45 ISDN connection cable
1 - Male to male header (interface connector)
3 - Screws with locking washers
ISDN Daughtercard
Figure 4-17 shows the ISDN daughtercard.
Figure 4-17. ISDN Daughtercard