ATTO Technology 1500D/E, 1550D/E operation manual Cabling, Cable types, Examples

Page 21

Cabling

Cables and devices must be chosen to maximize performance and minimize the electrical noise from the high-speed data transfers available with the SCSI protocol. Cabling and termination methods become important considerations for proper performance. SCSI cables and devices are subject to specific length and number limitations to deal with electrical problems that arise at increased operating speeds.

Cable types

Use high-quality cables rated for the type of SCSI transfers required: well-insulated SCSI cables ensure error free communications. Try to keep cable lengths as short as possible to ensure higher signal quality and performance.

Examples

The SCSI specification limits total bus cable length for single-ended SCSI in a non-UltraSCSI environment to 3 meters (combined length of both internal and external cable lengths).

In an UltraSCSI workgroup environment with a 7- drive tower, you are limited to 1.5 meters between the host and the tower, including the cabling for the tower. If the 7-drive tower requires 1 meter of cabling to connect all of its drives, the distance from the tower to the host must be .5 meters.

Note

UltraSCSI is very sensitive to SCSI bus noise, cable distances and the number of devices connected on the SCSI bus. Carefully connect your devices when working with UltraSCSI.

Exhibit 1.5-1 Various types of SCSI operate at different speeds and require different bus lengths to support a certain number of devices.

 

Bus speed

Bus width

Max. bus lengths in meters

Max. device

STA terms

MB/sec. max.

bits

 

 

 

support

Single-ended

Differential

LVD

 

 

 

 

 

 

 

 

 

 

 

Fast SCSI

10

8

3

25

n/a

8

 

 

 

 

 

 

 

Fast/WIDE SCSI

20

16

3

25

n/a

16

 

 

 

 

 

 

 

UltraSCSI

20

8

1.5

25

n/a

8

 

 

 

 

 

 

 

Ultra/WIDE SCSI

40

16

n/a

25

n/a

16

 

 

 

 

 

 

 

Ultra/WIDE SCSI

40

16

1.5

n/a

n/a

8

 

 

 

 

 

 

 

Ultra/WIDE SCSI

40

16

3

n/a

n/a

4

 

 

 

 

 

 

 

Ultra2 SCSI

80

16

n/a

n/a

12

8

 

 

 

 

 

 

 

Ultra2/WIDE SCSI

80

16

n/a

n/a

12

16

 

 

 

 

 

 

 

Ultra3/WIDE SCSI

160

16

n/a

n/a

12

16

 

 

 

 

 

 

 

12 Installation: SCSI connections

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Contents IPBridgeTM 1500D/E IPBridgeTM 1550D/E Page Page Contents Connecting Scsi devices to the Scsi port Serial port configuration commands Mapping commands Glossary Intelligent Bridging Architecture, the engineTerm Definition Introduction Setting up the iPBridge IPBridge1500 featuresIPBridge 1550 features Scsi Possible SAN/NAS ConfigurationAtto iPBridge 1500E Pin outs of the RJ11 connector, part number CBL-0911-001Exhibit 1.1-1 iPBridge 1500E board layout Installation instructionsAtto iPBridge 1500D Exhibit 1.2-1 iPBridge 1500D back panel Atto iPBridge 1550E Exhibit 1.3-1 iPBridge 1550E board layout Atto iPBridge 1550D Exhibit 1.4-1 iPBridge 1550D back panel Connecting Scsi devices to the Scsi port To connect Scsi devices to the Atto iPBridgeTo set Scsi port bus speed and transfer rates Cabling Cable typesExamples Configuring the iPBridge Connecting using the GbE portTo find the iPBridge Connecting using the serial port Using Atto ExpressNAVTo optimize ExpressNAV in Internet Explorer Select Internet OptionsUsing Telnet To connect using TelnetEnter Installation Configuration Scsi configuration Change default username, passwordTo change the default administrator password Managing the iPBridgeISCSI configuration Ethernet port configurationOEM configuration services MappingExpressNAV provides web-based interface Serial Port ConfigurationStatus To open an ExpressNAV sessionAdvanced CLI Configuration Bridge ConfigurationTo use the Advanced Configuration Restart FirmwareGet Set Command Parameter 1 Parameter Command conventionsCLI provides ASCII-based interface Configuration & Management CLI Command Defaults Example CLI commands summaryOEM configuration file Defaults Limits General use commands VerboseMode From information commands. Choices are enabled or disabledDiagnostic commands RouteDisplay CLI Error MessagesSCSIPortList SCSITargetsMaintenance commands Configuration CLI Scsi configuration commands SpeedWrite Serial port configuration commands SerialPortBaudRateSerialPortEcho Configuration CLI Ethernet commands ReadOnlyUsername ReadOnlyPasswordISCSI commands MultiTargetMode ISNSServerMapping commands AutoMapRoute Configuration CLI Privileged OEM configuration services ModelNumber OEM Config file supported commandsProductID VendorIDUse Command Line Interface Single target modeMapping devices Node namesMapping single vs. multiple target mode Use the ExpressNAV interface Multiple target modeTo remove an iSCSITarget ExampleUpdating firmware To use FTP over GbE to flash new firmware into the iPBridge\bridgefirmware\I1500110.ima Configuration & Management firmware update Appendix a Safety standards and compliances European Standards PWRA-0000-FRUPower Module for Atto FC Rack System FC Rack Enclosures with Power SuppliesAtto iPBridge 2500C Atto iPBridge 1500ECables/SCSI AccessoriesAppendix C Contact Atto Technology, Inc
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