ATTO Technology 1550D/E, 1500D/E operation manual Connecting Scsi devices to the Scsi port

1.5 Connecting SCSI devices to the SCSI port

The ATTO iPBridge SCSI port connects SCSI storage devices to the network.

The SCSI port is a bus capable of supporting up to15 devices in LVD mode and each bus is capable of 40, 80 or 160 MB/sec. (Ultra, Ultra2 or Ultra3) transfer rates.

The SCSI bus auto-negotiates the appropriate sync rates with the connected devices. If slower devices are mixed with faster devices, the bus will communicate at the rate of the slowest device, thus wasting the performance capabilities of the faster devices.

The iPBridge supports a wide variety of SCSI storage devices including stand-alone drives, removable drives, JBODs, RAIDs, tape, CD and DVD drives, changers and libraries.

To connect SCSI devices to the ATTO iPBridge

1Connect the cable from the SCSI device to the 68-pin HD SCSI port on the iPBridge.

2Check the type of cable, cable length limit and number of devices recommended for the port. See Exhibit 1.5-1.

Keep cable lengths as short as possible to ensure the highest signal quality and performance. These cable lengths include the wiring inside the devices.

3Set the IDs of the SCSI devices connected to the bridge to a value other than 7.

Use a sequential ID starting at 0 for each device. The SCSI port in the ATTO iPBridge has an internal factory setting ID of 7, typical for a SCSI initiator device.

Note

The entire SCSI bus will operate at the speed of the slowest device on that bus.

4Terminate the SCSI bus after the last device. The iPBridge is terminated internally.

To set SCSI port bus speed and transfer rates

Note

The preferred method to set parameters for the iPBridge is to use ATTO ExpressNAV. Refer to Configuring the iPBridge on page 13 and ExpressNAV provides web-based interface on page 19.

1Enter the Command Line Interface (see Configuring the iPBridge on page 13)

2Determine the current speed and transfer rates: type

get SCSIPortBusSpeed

get SCSIPortSyncTransfer

3SCSIPortBusSpeed controls the transfer rate at which the iPBridge will attempt to negotiate with its SCSI devices. Default is Ultra3

To change from the default or the current port bus speed, type

set SCSIPortBusSpeed sb [fastultra ultra2ultra3]

with sb being the SCSI bus number (0) and the speeds being Fast, Ultra, Ultra2 or Ultra3. See Exhibit 1.5-1.

4If you have completed configuration operations, type SaveConfiguration; if not, go on to the next command.

5SCSIPortSyncTransfer specifies whether synchronous SCSI transfers should be negotiated with devices on the SCSI port. The default is enabled. To change the setting, type

set SCSIPortSyncTransfer sb disabled

6When you have completed configuration operations, type SaveConfiguration to save the configuration for use after a power up or firmware restart.

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ATTO Technology Inc. iPBridge Installation and Operation Manual