Differences between 21U and 48U libraries 3555

This section references the differences between a library with the previous 21U height maximum and the current 48U height maximum.

The differences between these two types of libraries can be seen in their maximum configurations. Refer to Structure and supported library configurations.

Library Differences

  • The only hardware difference between the two configurations is the spooling cable. A new spooling cable assembly (also referred as spool) is designed to enable the library to extend up to 48U maximum height.
  • New library firmware 1.6.1.0 is needed to support a 48U library. Firmware 1.6.1.0 cannot be down-leveled to a previous firmware level.

  • The element numbering scheme is different for 21U and 48U libraries. Refer to Numbering scheme details.

  • A configuration saved on a 21U Library cannot be restored on a 48U Library. A configuration saved on a 48U Library cannot be restored on a 21U Library. Saved Configurations can only be restored on the same type of library.

How to Distinguish the Library Version

New part numbers are issued for 48U. The new 48U part numbers replace the existing 21U part numbers and the 21U part numbers will no longer be available.

  • From the base unit:
    To check on your base unit, refer to the image to find the part number label. See Figure 1.
    Figure 1. L3A 48U
  • From the spool:
    To identify if the Spool is for 21U or 48U, refer to Figure 2.
    Figure 2. 48U Label
  • From the GUI:
    Navigate to the 'Config/Spooling' field in GUI (Library > Dashboard > Actions > Properties). It will either display the library configuration, or the entire field will not be present. If the field is missing, it is a 21U Library with firmware older than 1.6.1.0. See Figure 3
    Figure 3. GUI Library Information

Transitions between Configurations

A 21U Library can use 21U parts or 48U parts. A 48U Library can ONLY use 48U parts. DO NOT put 21U CRUs into a 48U Library, it can cause very complex issues.

Only the base unit (L3A) determines the maximum height of a library. To upgrade to a 48U library, only a base unit needs to be ordered and replaced. A 21U base unit cannot be upgraded into a 48U base unit.

An expansion unit is ambivalent to the base unit limitations and can be transferred from a 21U library to a 48U library.