2 Messages
This chapter includes all SCSI messages, both supported and unsupported. Parts of this chapter come from Section 5, Logical Characteristics, of the SCSI standards (see page 11).
The message system provides an initiator and a target on the SCSI bus with a means of managing communication. The available messages are listed in this chapter.
Message Out support
Name | Code | Support |
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Abort | 06h | An abort condition is generated (see “Abort handling” on page 14). |
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Bus Device Reset | 0Ch | A reset condition is generated (see “Reset strategy” on page 13). |
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Extended Message | 01h | See “Extended Message Support” below. |
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Identify | 80h+ | The Identify Out message is sent by the initiator to identify the Logical |
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| Unit to be accessed and to set Disconnect Privilege. |
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Initiator Detected | 05h | The initiator has detected an error in the data being sent in a Command, |
Error |
| Data or Status phase. The drive will send a restore data pointers |
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| message to retry the data transfer. (See “Message In support” below for |
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| details). |
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| If the message is received immediately after an Identify message or after |
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| the Command Complete message has been sent, the drive will go Bus |
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| Free. |
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Message Parity Error | 09h | The initiator has detected a parity error in a message. The drive will retry |
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| the message. (See “Message In support” below for details). |
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| If the message is received immediately after an Identify message or after |
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| the Command Complete message has been sent, the drive will go Bus |
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| Free. |
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Message Reject | 07h | This message is sent when the initiator does not support a message sent |
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| by the drive or that the message is inappropriate. If the message being |
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| rejected is Disconnect, Synchronous Data Transfer Request or Wide Data |
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| Transfer Request, the operation continues without those features. For all |
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| other messages, the message is treated as an Abort message. |
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| If the message is received during a Command, Data or Status phase, |
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| immediately after an Identify message or after the Command Complete |
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| message has been sent, the drive will go Bus Free. |
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No Operation | 08h | This message has no effect and is ignored. |
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Messages
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