ATTO Technology 1500D/E - Manual (Page 20)

11
ATTO Technology Inc. iPBridge Installation and Operation Manual
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
1 Connect the cable from the SCSI device to the
68-pin HD SCSI port on the iPBridge.
2 Check 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.
3 Set 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.
4 Terminate 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.
1 Enter the Command Line Interface (see
Configuring the iPBridge on page 13)
2 Determine the current speed and transfer rates:
type
get SCSIPortBusSpeed
get SCSIPortSyncTransfer
3 SCSIPortBusSpeed 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 [fast|ultra|
ultra2|ultra3]
with sb being the SCSI bus number (0) and the
speeds being Fast, Ultra, Ultra2 or Ultra3. See
Exhibit 1.5-1.
4 If you have completed configuration operations,
type
SaveConfiguration ; if not, go on to
the next command.
5 SCSIPortSyncTransfer 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
6 When you have completed configuration
operations, type
SaveConfiguration t o save the
configuration for use after a power up or
firmware restart.