Mode Sense 6-byte (1Ah) and Mode Sense 10-byte (5Ah)

The Mode Sense commands return information about the library's operating mode parameters. The data can be truncated to the length specified in the allocation length field. The library returns a Mode Sense Parameter Header followed by one or more of the following mode pages:

Figure 2-12 Mode Sense 6-Byte Command

Description of "Figure 2-12 Mode Sense 6-Byte Command"

Figure 2-13 Mode Sense 10-Byte Command

Description of "Figure 2-13 Mode Sense 10-Byte Command"

LLBA (10-byte only)

Set this to 0. The library will return 0 for LONGBLA in the parameter data.

DBD (Disable Block Descriptor)

The library ignores this field.

Page Control

0h (00b) = Current Values. The library returns the requested pages with each supported parameter set to its current value.

1h (01b) = Changeable Parameter Values. The library returns the requested pages indicating which parameters the initiator can change (1 indicates a changeable parameters and 0 indicates an unchangeable parameter).

2h (10b) = Default Values. The library returns the requested pages with each supported parameter set to its default. The default values are the same as the current values. Parameters not supported by the library are set to 0.

3h (11b) = Saved Values. This option is valid only with mode pages that can be saved. If the mode page cannot be saved, then a Check Condition is returned

Page Code

HP Bridged Tape Drive:

02h = Protocol Specific Disconnect/Reconnect page
18h = Protocol Specific Logical Unit page
19h = Protocol Specific Port Control page
1Ch = Informational Exceptions TapeAlert page
1Dh = Element Address Assignment page
1Eh = Transport Geometry page
1Fh = Device Capabilities page
3Fh = All pages (in the above order)

IBM Bridged Tape Drive:

1Ch = Informational Exceptions TapeAlert page
1Dh = Element Address Assignment page
1Eh = Transport Geometry page
1Fh = Device Capabilities page
3Fh = All pages (in the above order)

SubPage Code

Specifies which mode subpages are returned by the library. The supported mode subpages depend on the bridged tape drive.

HP Bridged Tape Drive: The field indicates the Serial Attached SCSI Port Control subpage, when the protocol is Serial Attached SCSI and the Page Code is set to 19h. The following subpages are supported:

01h = Serial Attached SCSI Phy Control and Discover Mode Subpage

02h = Serial Attached SCSI Shared Port Control Mode Subpage

03h = Serial Attached SCSI Enhanced Phy Control Mode Subpage

IBM Bridged Tape Drive: This field must be 00h. There are no supported mode subpages.

Allocation Length

The allocation length field specifies the maximum number of bytes that the initiator has allocated for data returned from the Mode Sense command. The library transfers either the number of bytes specified by the allocation length field or all of the available mode sense data, whichever is less. The allocation length depends on the mode page and the bridged tape drive. The maximum number of bytes returned by the library is 68h (104d) bytes for Mode Sense 6 and 6Ch (108h) bytes for Mode Sense 10.

A value of 00h indicated that no mode sense data is to be transferred. This condition is not considered an error.

For Mode Sense 6-byte:

HP Bridged Tape Drive:

04h = Mode Sense 6 Parameter Header Length
08h = Mode Sense 10 Parameter Header Length
10h = Disconnect Reconnect Page Length
08h = Logical Unit Page Length
08h = Fibre Channel Port Control Page Length
10h = SAS Port Control Page Length
64h = SAS Phy Control and Discover Mode Subpage Length
0Ch = Informational Exceptions Tape Alert Mode Page Length
14h = Element Address Assignment Page Length
04h = Transport Geometry Page Length
14h = Device Capabilities Page Length

IBM Bridged Tape Drive:

04h = Mode Sense 6 Parameter Header Length
08h = Mode Sense 10 Parameter Header Length
0Ch = Informational Exceptions Tape Alert Mode Page Length
14h = Element Address Assignment Page Length
04h = Transport Geometry Page Length
14h = Device Capabilities Page Length

IBM Bridged Tape Drive:

08h = Mode Sense Parameter Header Length
0Ch = Informational Exceptions Tape Alert Mode Page Length
14h = Element Address Assignment Page Length
04h = Transport Geometry Page Length
14h = Device Capabilities Page Length

Mode Sense Parameter Header

Figure 2-14 Mode Sense 6-Byte Parameter Header

Description of "Figure 2-14 Mode Sense 6-Byte Parameter Header"

Figure 2-15 Mode Sense 10-Byte Parameter Header

Description of "Figure 2-15 Mode Sense 10-Byte Parameter Header"

Mode Data Length: The bytes of parameter information available regardless of the allocation length. This value excludes the Mode Data Length byte, but includes three additional bytes (for Mode Sense 6-byte) or six additional bytes (for Mode Sense 10-byte) and the length of any mode pages that follow.
Block Descriptor Length (not supported): The library returns 0.

FC Disconnect/Reconnect Page

This is the same as the Mode Select FC Disconnect/Reconnect Page.

SAS Disconnect/Reconnect Page

This is the same as the Mode Select SAS Disconnect/Reconnect Page.

FC Logical Unit Control Page

This is the same as the Mode Select Fibre Channel Logical Unit Page.

SAS Logical Unit Page

This is the same as the Mode Select SAS Logical Unit Page.

FC Port Control Page

This is the same as the Mode Select Fibre Channel Port Control Page.

SAS Port Control Page

This is the same as the Mode Select SAS Port Control Page.

SAS Phy Control and Discover Mode Subpage

This is the same as the Mode Select SAS Phy Control and Discover Mode Subpage.

SAS Shared Control Mode Subpage

Description of the illustration l207_287.png

PS (Parameters Saveable)

The library returns 0.

SPF (SubPage Format)

The library returns a value of 1 for the SubPage Format bit, indicating this page uses the sub_page mode page format.

Page Code

The value 19h identifies the page as the SAS Port Control mode page.

Subpage Code

The value 02h identifies the sub-page as the SAS Shared Port Control Mode Subpage.

Protocol Identifier

06h = Serial Attache SCSI protocol.

Power Loss Timeout

This field contains the maximum time, in one millisecond increments, that a target port shall respond to connection requests with OPEN_REJECT (RETRY) after receiving NOTIFY (POWER LOSSEXPECTED).

The value 0000h indicates that maximum time is vendor-specific.

SAS Enhanced Phy Control Subpage

Description of the illustration l207_288.png

PS (Parameters Saveable): The library returns 0.
SPF (SubPage Format): The library returns a value of 1 for the SubPage Format bit, indicating this page uses the sub_page mode page format.
Page Code: The value 19h identifies the page as the SAS Port Control mode page.
Subpage Code: 03h = SAS Enhanced Phy Control Mode Subpage
Protocol Identifier: 06h = Serial Attache SCSI protocol.
Generation Code: This field is a one-byte counter that shall be incremented by one by the device server every time the values in this mode page are changed.
Number of Phys: This field contains the number of phys in the SAS target device and indicates the number of Enhanced Phy Control Mode Descriptors in the Enhanced Phy Control Mode descriptor list.

Enhanced Phy Control Mode Descriptor Data

Description of the illustration l207_289.png

Phy Identifier

A unique Phy Identifier is returned for each Phy.

Descriptor Length

The library returns a value of 10h (16d) bytes.

Programmed, Current, and Attached Phy Capabilities

This field indicates the SNW-3 (Speed Negotiation Window) Phy capabilities bits that are going to be transmitted in the next link reset sequence containing SNW-3 as defined below. If the last link reset sequence did not include SNW-3, then the field will be set to 00000000h.

Negotiated SSC

The Negotiated SSC bit is only valid when the Negotiated Physical Link Rate is great than or equal to 8h. When valid:

0 = SSC is enabled.

1 = SSC is disabled.

Hardware Muxing Support

0 = The Phy does not support multiplexing.

1 = The Phy supports multiplexing.

Phy Capabilities Data

Description of the illustration l207_290.png

TX SSC Type

The value 0 indicates that the phy's transmitter uses down-spreading SSC when SSC is enabled (for example, the phy is a SAS phy), or that the phy does not support SSC.

The value 1 indicates that the phy's transmitter uses center-spreading SSC when SSC is enabled (for example, the phy is an expander phy).

Requested Logical Link Rate

This field indicates if the Phy device supports multiplexing and, if so, the logical link rate that the Phy device is requesting.

G* With and Without SSC

0 = Does not support

1 = Supports that G level

Parity

The Parity bit shall be set to one or zero such that the total number of SNW-3 Phy device capabilities bits that are set to one is even, including the Start bit and the Parity bit.

Informational Exceptions Tape Alert Control Page

This is the same as the Mode Select Information Exceptions TapeAlert Page.

Element Address Assignment Page

This is the same as the Mode Select Element Address Assignment Mode Page.

Transport Geometry Mode Page

Description of the illustration slk_091.png

PS (Parameters Savable)

The library returns 0.

Page Code

1Eh = the Transport Geometry mode page.

Page Length

The number of additional types of transport geometry descriptor data to follow the header. Each descriptor has two bytes of information.

02h = The library has one transport mechanism.

Rotate

0 = The library does not use multiple-sided media.

Member Number in Transport Element Set

Identifies the transport element in the system.

00h = The library has one transport element.

Device Capabilities Page

DT — Data Transfer Element (drive)
I/E — Import/Export Element (CAP cells)
ST — Storage Element (cartridge storage cell)
MT — Medium transport (robot hand)

Description of the illustration slk_092.png

PS (Parameters Savable): The library returns 0.
Page Code: 1Fh = The Device Capabilities mode page.
Page Length: 12h = 18 bytes of device capabilities data to follow.
StorDT: 1 = A tape drive can function as element storage.
StorI/E: 1 = A CAP cell can function as element storage.
StorST: 1 = A cartridge cell can function as element storage.
StorMT: 0 = The robot hand cannot function as element storage. You cannot use the robot as the source or destination of a move.
MT > DT, MT > I/E, MT > ST, MT > MT, ST > MT, I/E > MT, DT > MT: 0 = The robot hand (MT) cannot be the source or destination of a move.
ST > DT, ST > I/E, ST > ST, I/E > DT, I/E > I/E, I/E > ST, DT > DT, DT > I/E, DT > ST: 1 = Tape drives (DT), CAP cells (I/E), and cartridge cells (ST) are valid sources or destinations for a move.
All <> Parameters: 0 = The library does not support the exchange medium command.