Logical-host ids are defined and SPs associated with them using the Teradata Database Configuration Utility, referred to in Utilities (B035-1102). The Host Type Designator is always 'IBM'. In that document, SPs are referred to as PEs.
CPs and NPs are associated with a Logical-host using the Teradata Database Parallel Upgrade Tool. For information, see the Parallel Upgrade Tool (PUT) Reference.
When multiple Teradata Databases have Logical-host ids with CPs or NPs accessed by TDPs in the same operating system image, all these Logical-host ids must be unique.