SCSI target devices provide a number of SCSI diagnostic pages. These can be used by a Send Diagnostic command to tell a target device to run a specialised self-test. The Receive Diagnostic Results command is used where the results from the self-test operation are non-trivial. Most of the common SCSI devices such as disk-drives support only one or two diagnostic pages. SES devices can support many diagnostic pages. List of SCSI diagnostic pages SCSI uses a one byte addressing scheme for diagnostic pages, allowing for a total 256 possible pages. There is a standard map of diagnostic page addresses shown below. Note that any given SCSI device type will only support a subset of these diagnostic pages. Some diagnostic pages have two different meanings depending on whether they are being used for control purposes (Send Diagnostic command) or to interrogate status (Receive Diagnostic Results command). Those cases are shown as double entries in the table below using this convention: "control definition / status definition". 00h - list of supported diagnostic pages 01h - SES - configuration 02h - SES - enclosure control / enclosure status 03h - SES - help text 04h - SES - string out / string in 05h - SES - threshold out / SES threshold in 06h - SES - obsolete 07h - SES - element descriptor 08h - SES - short enclosure status 09h - SES - enclosure busy 0Ah - SES - additional element 0Bh - SES - subenclosure help text 0Ch - SES - subenclosure string out / SES subenclosure string in 0Dh - SES - supported SES diagnostic pages 0Eh - SES - download microcode control / SES download microcode status 0Fh - SES - subenclosure nickname control / SES subenclosure nickname status 10h-1Fh - SES - vendor-specific 20h-2Fh - SES - reserved 30h-3Eh - reserved 3Fh - used by the SCSI transport layer 40h - disk/optical - translate address 41h-7Fh - reserved 80h-FFh - vendor-specific SCSI