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Host communications are provided by way of a SCSI interface.
The high-density 68-pin SCSI-3 connector can be cabled to a host with a
narrow 50-pin SCSI-2 with an adapter.
SCSI ID
The EmPack’s SCSI device number is set by either a rotary switch on the
foundation board, jumpers on a back header, or a push button switch on the external enclosure. This setting can also be
overridden with a soft ID set in non-volatile memory with a utility program.
Multiple Foundation Boards
Multiple EmPacks can be on the same SCSI bus with other
peripherals with no degradation in performance provided the
aggregate data bandwidth does not exceed the SCSI limitations.
The table to the right shows the maximum number of devices and data
throughput for each of the SCSI buses.
Single-ended vs Differential SCSI
The EmPack can be ordered with either SCSI interface.
Most host SCSI controllers are single-ended which have cable
length limits as shown in the table to the right.
If greater cable length is required, specify the differential
option in the EmPack’s foundation board part code and be
sure you have a differential SCSI interface for the host computer.
SCSI Termination
The EmPack can be configured using jumpers on a back header
to provide termination and termination power to the SCSI bus. |
SCSI Bus Type |
Max Devices |
Max Data Rate |
| fast, narrow |
7 |
10 MB/sec |
| fast, wide |
15 |
20 MB/sec |
| ultra, narrow |
7 |
20 MB/sec |
| ultra, wide |
15 |
40 MB/sec |
max devices
does not include system controller
max data rates are per SCSI specifications
SCSI Speed |
Max Cable Length |
Async |
6 meters |
Sync |
6 meters |
Fast |
3 meters |
Ultra |
1.5 meters |
max cable lengths are per SCSI specifications |
