Agilent Technologies 1660A Series User Reference page 156

The Configuration Menu
Unassigned Pods List
Illegal Configuration
When both analyzers are turned on, the first pod pair 1,2 and the last pod
pair (5,6 in the 96 channel model or 7,8 in the 128 channel model) cannot be
assigned to the same analyzer machine. If this configuration is set, the
analyzer will display a reassignment menu. Use this reassignment menu to
configure the pod assignment automatically to a legal configuration.
Configuration Reassignment Menu
10–6