Part locations and location codes

You can find part locations by using location codes. Illustrations are provided to help you map a location code to a position on the server or expansion unit.

Using location codes

For additional information about reading your location code, use the following table to link to a specific topic.

Location code topics that might be of interest	Description
Location code overview	Contains background information on the use of location codes.
Physical location codes	Provides a definition for physical location code.
Logical location codes	Provides a definition for a logical location code.
Location code format	Provides descriptive information of the U`n` value in the location code string. For example, U5887.001.
Location code labels	Provides a table that identifies and defines the location code labels. The location code labels begin with an alphabetic character and follow the system serial number. For example, U5887.001.10ABCDE-P3-C31-T2-L23. (The system serial number is the 10ABCDE in the previous example.) The P3, C31, T2, and L23 all contain an alphabetic character that is identified in the Location code labels table.
Worldwide unique identifier	Provides a definition for the worldwide unique identifier. This group of digits follows the resource code labels and always begins with the letter `W`.

Location code overview

Servers (system unit and expansion units) use physical location codes to provide mapping of replaceable units. Location codes are produced by the server's firmware, which structures them so that they can be used to identify specific parts in a system. The location code format is the same for all servers.

If you are working with a specific location code, the feature immediately follows the first character (U5887). See the Unit type and locations table.

If the location code ends with -Txx-Lxx, the server's firmware could not identify the physical location. When a physical location cannot be identified, a logical location code is provided. Where logical location codes occur in enclosures, the locations topic for the enclosure has the known conversions listed. For logical location codes with no conversion, contact your next level of support.

If the location code begins with UTMPx, the expansion I/O unit's machine type, model, and serial number have not been set yet and this is a temporary unit identifier. To identify the unit, examine the display panels on all of the expansion I/O units connected to the server until you find one with the same characters in the first 5 digits of the top line in the unit's display. Record the unit's real machine type and model from the unit label. Match the unit's machine type and model in the Unit type and locations table, and follow the link to determine the service information.

Note: If locations for units are not in the preceding format, either they are not supported or there is a problem in the firmware. Contact your next level of support.

Physical location codes

Physical location codes provide a mapping of logical functions and components (such as backplanes, removable modules, connectors, ports, cables, and devices) to their specific locations within the physical structure of the server.

Logical location codes

If the physical location cannot be mapped to a physical location code, the server's firmware generates a logical location code. A logical location code is a sequence of location labels that identifies the path that the system uses to communicate with a given resource.

Note: A resource has as many logical location codes as it has logical connections to the system. For example, an external tape device connected to two I/O adapters will have two logical location codes.

An example of a logical location code is:

U5887.001.10ABCDE-P3-C31-T2-L23

The first part of the location code (through the T2 label) represents the physical location code for the resource that communicates with the target resource. The remainder of the logical location code (L23) represents exactly which resource is indicated.

Location code format

The location code is an alphanumeric string of variable length, consisting of a series of location identifiers, separated by a dash. An example of a physical location for a fan is Un-A1.

The first position, represented by Un (where n is equal to any string contained between the U and the hyphen) in the preceding example, is displayed in one of the forms in the following table.

Note: In location codes, the U is a constant digit; however, the numbered positions following the U are variables and are dependent on your server. Each column defines the numbers that follow the U in the beginning of the location code.

Machine type and model number in a location code	Feature codes and sequence numbers in a location code
`Utttt.mmm.sssssss-A1`	`Uffff.ccc.sssssss-A1`
The leftmost code is always U.	The leftmost code is always U.
`tttt` represents the unit type of the enclosure (drawer or node).	`ffff` represents the feature code of the enclosure (drawer or node).
`mmm` represents the model of the enclosure. Notes: On a single node system, the characters of the location code that indicate the model number might be replaced with ND1. On a 9080-M9S system, the model number might be replaced by a more specific enclosure indicator. SC1 indicates the system control unit, and ND1 through ND4 indicate system node 1 through system node 4.	`ccc` represents the sequence number of the enclosure.
`sssssss` represents the serial number for the enclosure.	`sssssss` represents the serial number of the enclosure.
Note: The `mmm` or `ccc` number might not be displayed on all location codes for all servers. If the `mmm` value is not displayed, the location code is displayed in one of the following forms: `Utttt.sssssss-A1` `Uffff.sssssss-A1`

The location code is hierarchical; that is, each location identifier in the string represents a physical part. The order (from left to right), in which each identifier is shown, allows you to determine which parts contain other parts in the string.

The dash (-) separator character represents a relationship between two components in the unit. In the example of the fan, whose location code is Un-A1, the dash shows that the fan (A1) is contained in the base unit (or Un). Modules, adapters, cables, and devices are all parts that are plugged into another part. Their location codes always show that they are plugged into another part as components of the server. Another example follows: Un-P1-C9 is a memory DIMM, with memory DIMM (C9) plugged into a backplane (P1), which is inside the unit (Un).

Note: For devices, certain error conditions might cause an IBM® i device to display the device location in an AIX® format.

Table 1. Unit type and locations
Unit type (Utttt)	Link to location information
U78D3.`mmm`, where `mmm` is 001 or ND1	5105-22E, 9008-22L, 9009-22A, 9009-22G, 9223-22H, or 9223-22S locations
U78D2.`mmm`, where `mmm` is 001 or ND1	9009-41A, 9009-41G, 9009-42A, 9009-42G, 9223-42H, or 9223-42S locations
U78D4.`mmm`, where `mmm` is 001 or ND1	9040-MR9 locations
U78D6.SC1	9080-M9S system control unit locations
U78D5.`mmm`, where `mmm` is ND1, ND2, ND3, or ND4	9080-M9S system node locations
U5887.001	5887 disk drive enclosure locations
U78CD.001	EMX0 PCIe Gen3 I/O expansion drawer locations
UESLL.001	ESLL or ESLS locations
UESLS.001	ESLL or ESLS locations

Location code labels

The location code label represents a physical part of the server. The following table describes the prefixes of location code labels.

Note: These labels apply to system units only.

Table 2. Prefixes of location code labels for system units
Prefix	Description	Example
A	Air-moving device	Fan, blower
C	Card connector	IOP, IOA, DIMM, processor card
D	Device	Diskette, control panel
E	Electrical	Battery, power supply, ac charger
L	Logical path SAS target	Integrated drive electronics (IDE) address, Fibre Channel LUN
N	Horizontal placement for an empty rack location
P	Planar	System backplane
T	Port
U	Unit
V	Virtual planar
W	Worldwide unique ID
X	EIA value for an empty rack location
Y	Firmware FRU

Worldwide unique identifier

The location code label for the worldwide unique identifier consists of the prefix W followed by a maximum of 16 uppercase hexadecimal digits with no leading zeros. A location code might not consist of a worldwide unique identifier. When present, the worldwide unique identifier location label follows the location label of the resource that interfaces with the resource that has the worldwide unique identifier, usually a port.