We manufacture and stock a complete line of LVD (Low Voltage Differential) SCSI cables. These LVD SCSI cables are the perfect
compliment to Ultra SCSI systems. All our LVD cables have backward capability and as such are suitable for all applications. Our LVD cables are available in 3, 4 and 6 connector versions. The LVD/SE
terminator incorporates the latest technology and can sense if the bus is running LVD or SE and terminates accordingly.
LVD SCSI Features:
- 34 pairs laminated flat cable
- For use with Ultra 2 SCSI card mainboard
- Allows up to 6 devices to be daisy chained
- I/0 speed of up to 160mbps
- Double sided laminate for extra flexibility
LVD SCSI FAQ.
What is LVD SCSI?
LVD, which stands for Low Voltage
Differential, was introduced in the SPI-2 document of SCSI-3. It is also called Ultra 2 or Fast-40 SCSI. It uses 3 volt instead of 5 volt logic level and is not directly compatible with the
"old" differential (HVD) SCSI. LVD again doubles SCSI data throughput to 40 Megatransfers/sec. Cable lengths are 12 m (40 ft). Single initiator-single target applications may use up to 25 m (82
ft) of cable. The "multimode" implementation of LVD is backward compatible with single-ended SCSI. However, connecting one single-ended peripheral to a multimode LVD bus will cause the entire
bus to switch to the single-ended mode with the single-ended limitations on data throughput and cable length. LVD can be interconnected with HVD by the use of a SCSI expander called an LVD to HVD
What are the benefits of LVD SCSI?
In addition to the
obvious benefits of longer maximum cable length than single-ended and a doubling of data throughput, there are a number of other benefits. LVD/MSE and single-ended offer some compatibility. The lower
operating voltage of the LVD bus means lower power dissipation, so the differential drivers can be included on the LVD ASIC rather than having to mount them external to the chip. This results in smaller
boards, less heat dissipation, higher reliability and lower cost. Also, manufacturers will no longer have to design and build devices with both single-ended and differential interfaces. This results in
Is LVD SCSI backward compatible?
LVD is backward compatible
through the single-ended interface if it is multimode LVD. It is doubtful that anyone will build LVD devices that are not multimode. Remember that connecting a single-ended device to a LVD/MSE bus will
cause the entire bus to switch to the single-ended mode with its data throughput and cable length limitations. To add a single-ended peripheral to an LVD bus and preserve the data throughput and cable
length of LVD, you can use a SCSI expander called an LVD to SE or LVD/MSE to LVD/MSE converter. This converter divides the SCSI domain into two bus segments - one segment will operate at the LVD data
throughput and cable length and the other bus segment will operate at the single-ended data throughput and cable length.