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
The iPBridge supports a wide variety of SCSI storage devices including
To connect SCSI devices to the ATTO iPBridge
1Connect the cable from the SCSI device to the
2Check the type of cable, cable length limit and number of devices recommended for the port. See Exhibit
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
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
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.
11
ATTO Technology Inc. iPBridge Installation and Operation Manual