Single Connector Attachment
（重定向自Single Connection Attach）
![SCSI hard drives showing 80-pin SCA connector (top) and 68-pin connector and separate power and configuration jumpers (bottom)](/Images/godic/202502/11/SCSIHardDriveConnectors0545.jpg")
![SCSI backplane with 80-pin SCA connectors. Hard Drives are mounted on proprietary hot-swappable caddies.](/Images/godic/202502/11/SCSI-SCA-backplane0545.jpg")
![SPARCstation 20 drive in cradle](/Images/godic/202502/11/SPARCstation20_scsi_cradle_with_drive0545.jpg")
Single Connector Attachment, or SCA, is a type of connection for the internal cabling of SCSI systems. There are two versions of this connector: the SCA-1, which is deprecated, and SCA-2, which is the most recent standard. In addition there are Single-Ended (SE) and Low Voltage Differential (LVD) types of the SCA.