ATTO Technology operation manual Connection considerations, Termination

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Connection considerations

the connector), followed by the Narrow devices.

If using a combination of Wide 16-bit devices and

Please refer to the documentation you received

Narrow 8-bit devices on the same connector,

with your SCSI devices to determine if your

Wide devices must be connected first (closest to

device is Wide or Narrow.

Exhibit 3.1-2 Several types of internal and external cable connectors.

Cables,

Termination

The SCSI bus is a chain of SCSI devices. The devices at both ends of any SCSI chain must be terminated for the SCSI bus to function correctly. A SCSI device chain can be configured in three different ways: internal, external and an internal/external SCSI device chain.

The ATTO ExpressPCI SCSI adapter is a SCSI device and may require termination depending upon the configuration. Be sure to use the correct terminator. Single-Ended, Low Voltage Differential and Differential SCSI buses use different types of terminators that should not be mixed.

Single-Ended ATTO ExpressPCI PSC/DC

incorporates advanced termination circuitry to automatically configure its own termination.

Exhibit 3.1-3 Two LEDs on the top edge of the ATTO ExpressPCI PSC/DC provide feedback on its automatic termination setting.

LED1

LED 2

ATTO ExpressPCI-PSC

(Low Term)

(High Term)

termination

 

 

 

On

On

All 16 data bits terminated

 

 

 

Off

Off

No termination

 

 

 

Off

On

Upper 8 bits terminated

 

 

 

You should not have to manually adjust the termination of your adapter unless you a narrow (8 bit) device attached to the external port AND a

wide (16 bit) device attached to the internal port of your ATTO ExpressPCI PSC/DC OR if you attached a narrow (8 bit) device to the internal WIDE (16 bit) connector and a WIDE (16 bit) device to the external port. You must manually terminate the adapter using ATTO ExpressPCI Utilities program with the termination option set to Upper.

The ATTO ExpressPCI SCSI adapter only controls its own termination. You must terminate the last device of both the internal SCSI chain and the external SCSI chain.

termination

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Contents Page Page Contents Scsi Connectors FeaturesPower Requirements Environmental and Physical SpecificationsFeatures, benefits Glossary Scsi is a key technology for storageGlossary System requirements Installing the ExpressPCI Scsi Host AdapterInstallation Atto ExpressPCI PSC Scsi adapter Examples ConnectorsCable types Termination Connection considerationsWide devices first closest to the connector To set up cabling and terminationCables, termination Windows Server 2003 & Windows 2000/XP Installing and Updating Device DriversDrivers Re-flashing Firmware in Windows Updating Drivers and Re-flashing Firmware in Mac OS Set registry for large block transfers Set up RAID groups with Atto ExpressRAIDUse the latest Atto driver Analyze your I/Os Increase transfer sizeTroubleshooting Troubleshooting FCC standards radio and television interference Appendix a Standards and compliancesAppendix B Scsi host adapter selection guide Specific featuresExpressPCI Express PCI Appendix C Fibre Channel host adapter guideAppendix D Contact Atto Technology, Inc

ATTO ExpressPCI Ultra/WIDE SCSI Host Adapters Express PCI PSC: Single-Channel Single-Ended Ultra/WIDE ExpressPCI DC: Dual-Channel Single-Ended Ultra/WIDE specifications

ATTO Technology is a leading provider of cutting-edge storage connectivity solutions, and their line of ATTO ExpressPCI Ultra/WIDE SCSI Host Adapters has showcased the company’s commitment to performance and reliability for demanding data applications. Specifically, the ExpressPCI PSC (Single-Channel Single-Ended Ultra/WIDE) and the ExpressPCI DC (Dual-Channel Single-Ended Ultra/WIDE) models cater to different user needs while maintaining industry standards.

The ATTO ExpressPCI PSC is designed for environments where a single channel is sufficient to meet the connectivity demands. This single-ended adapter supports Ultra/WIDE SCSI technology, enabling data transfer rates of up to 40 MB/s. The PSC is perfect for users who require efficient storage solutions without the complexity of handling multiple channels. With its robust design, this adapter excels in various applications, from small business servers to high-performance workstations, offering reliability in demanding environments.

On the other hand, the ATTO ExpressPCI DC doubles the capability with its dual-channel architecture. This feature allows for two independent SCSI buses, effectively doubling the potential data throughput. By utilizing ultra/WIDE SCSI technology, the DC can achieve a combined throughput of 80 MB/s, making it an optimal choice for users needing higher performance for tasks such as video editing, data intensive applications, and backups. The dual-channel configuration provides advantages in multitasking, enabling the simultaneous operation of multiple drives or devices.

Both models incorporate advanced technologies such as automatic bus termination and active negation, ensuring optimal signal integrity and reliability. Additionally, ATTO’s exclusive Advanced Data Flow Management technology enhances performance by intelligently managing data transfer to optimize bandwidth utilization, which is key in environments where data transfer speed and reliability are crucial.

Another noteworthy characteristic is the high compatibility with various operating systems and SCSI devices, making the ExpressPCI Ultra/WIDE SCSI Host Adapters versatile and easy to incorporate into existing systems. They support a wide range of SCSI drives and peripherals, ensuring that users can leverage their investment in both current and future technologies. In summary, the ATTO ExpressPCI Ultra/WIDE SCSI Host Adapters—PSC and DC—represent robust solutions that blend speed, reliability, and flexibility, catering to the diverse needs of businesses and advanced users alike. With their proven performance, these adapters continue to be an important asset in high-demand data environments, showcasing ATTO's dedication to innovation in the storage connectivity realm.
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