| Active BackPlane is allowed to install up to 18 PCI devices. Are there any conflicts in that case? | | There are not. All conflicts can be settled by means of PCI Bridge chip installed on an Active BackPlane, with the help of cascading and interruptions control. For more details see description of the chip manufacturer . It is need to emphasize, that during installation of large quantity of PCI cards it is necessary to specify: how many PCI cards supports the driver (software) simultaneously. | | [questions] |
| How many ISA and PCI I/O cards can I add to the Passive Backplane? What are the restrictions for the installed cards quantity? What you can do, if there is a shortage of free slots? Is it possible 'to link up' an additional passive father card, when the p | It is possible to install 14-slots in a Passive BackPlane 4 PCI cards, 1 PICMG card and up to 8 ISA cards. Notice: processor ventilator for PICMG form factor processor cards can take space for 2-3 free slots, and it is difficult to install full-size expansion boards. By the way, 1 slot is simultaneously used for PCI/ISA cards, and 1 slot can be used for additional ports connectors (RS, LPT or others). As for the installation of plenty ISA cards, the additional restriction is stipulated with free interruptions on a ISA-bus.
Notice: the processor cards support up to 20 ISA (ISAMAX) cards. | | [questions] |
| SCSI ULTRA160/m what is that? | On the 14th of September of 1998 seven leading manufacturers of the computer systems and data storage systems announced the support of the further SCSI interface developement for increasing its effectiveness, reliability and controllability. The new interface was named Ultra 160/m SCSI. SCSI got the following innovations: DTR up to 160Mbps, improved controllability, self-acting tests of the interface operation capability and improved reliability due to the CRC. If Ultra 160/m SCSI is used with LVD interface, it is possible to connect cables up to 12 meters length and provide the full vertical compatibility.
SCSI technology continues developing taking into account growing requirements of the I/O channel capacity. This interface with 15-years operational experience is stable, easy to install, supports multiple OS and provides the full vertical compatibility.
SCSI ULTRA160/m what is that?
T10 ANSI Committee adds parallel interface standard SCSI (SPI-3). This document is the basis of the Ultra 160/m SCSI technology. Significant changes were applied to the existent SCSI protocol in order to increase output, controllability and reliability. All changes are added to the existent SCSI protocol to provide full compatibility. Three new main Ultra 160/m SCSI components:
- Double Transition Clocking
- CRC
- Domain Validation
What technologies Ultra 160/m SCSI interface is based on?
In order to increase the data transmission rate in two times up to 160Mbps, Ultra 160/m SCSI interface uses both signal's wavefronts - inquiry/approval for synchronization. This solution provides developers with the possibility to obtain high performance or reliability. They can either increase data transmission rate up to 160 Mbps or increase the reliability of the Ultra2 SCSI (80Mbps) by dropping synchronization frequency. Another improvement of the Ultra 160/m SCSI interface includes self-acting tests of the interface efficiency for controllability improvement and CRC employment for data transmission reliability.
Double synchronization of the data transission
Double synchronization of the data transission provides the employment of both signal's wavefronts - inquiry/approval for synchronization. Data transmission rate can be doubled by increasing the frequency on the communication lines in two times. For instance, signal - inquiry/approval in Ultra2 SCSI interface has frequency of 80MHz, whereas data is transmitted on 40MHz, or 80Mbps on the 16-bit bus. With the help of using both wavefronts of the same signal, data transmission rate goes up to 80MHz or up to 160Mbps on the same 16-bit bus.
Performance increase
Double synchronization increases the channel capacity during data transmission from 80Mbps to 160Mbps. Data transmission channel capacity is the essential feature for the systems working under Windows NT, UNIX workstations, video editing stations and local bulk storage devices.
Reliability increase
During data transmission double synchronization, synchronizing clock frequency can be reduced in two times. The impulses with bigger length decrease problems by reducing requirements to the cables, connectors, terminators etc. Double synchronization of the data transission reduces the synchronizing clock max. frequency (REQ/ACK) without deceleration of the data transmission rate.
Data integrity control with CRC
Ultra 160/m SCSI uses data integrity control with CRC to provide data transmission reliability. CRC raises the reliability level during data transmission and ensures the data full integrity. CRC using significantly changes the quantity of undetected errors. Because, it is the same method which is used in FDDI, local networks on the basis of the CSMA-CD protocol, and in the fiber data transmission channels.
Ultra3 SCSI CRC detects:
All single bit errors
All double bit errors
All odd bit errors
All errors of the packet up to 32 bit
Domain Validation
Domain Validation is the third part of the Ultra 160/m SCSI interface. This intelligent technology provides checking of the data storage subsystem, including connecting cables, backplanes, terminators etc. Domain Validation ensures the operationability of the system within required specifications. If the danger of data loss appears, then the system slows down the transmission rate (frequency goes down automatically). This method is frequently used by modems and facsimile sets. Domain Validation increases the system performance due to decrease of the repeated inquiry quantity. Tests are provided automatically, it allows to avoid the changes of the controller generic parameters, BIOS parameters manual setting.
Ultra 160/m SCSI - we need the stable interface.
SCSI interface has fifteen year practice of vertical and horizontal compatibility. Jump to the Ultra 160/m SCSI - is the only possible way to protect your costs. | | [questions] |
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