 |
|
|
|
FT
Subsystems
Chapter 2 - Resource Subsystem
Overview
Power Supply
Processor Bay
Multiplexor/Front Panel
Drive Bay
Input/Output
Auxiliary Junction Panels
System Considerations
The Cubix Fault Tolerant Resource Subsystem contains a 16 slot passive backplane divided into groups. A group consists of a series of PC slots connected together. Also included is a disk drive bay capable of housing nine 3.5" disk drives, optionally up to eighteen 2.5" drives. Since the backplane is a standard ISA or EISA component, PC-compatible boards (such as network interface controllers) are supported. With a Cubix BC Series bus controller card and a network interface controller (NIC) inserted into each group, the Resource Subsystem can provide multiple network workstations in a single unit. The number of workstations and expansion slots depends upon the configuration of the 16-slot backplane. For example, the ISA or EISA/ISA 16slot segmented backplane can be configured to have four groups of PC slots with each group containing four slots. With a BC Series board installed in each group, this is functionally equivalent to four AT-class computers, each with three expansion slots.
The Resource Subsystem ISA Backplane is available in 15 specific configurations; these are defined in Appendix A. The Resource Subsystem EISA and EISA/ISA backplanes are available in 17 configurations. These are also defined in Appendix A. Following is a general description pertaining to any of the Resource Subsystem configurations.
The Cubix Fault Tolerant (FT) Resource Subsystem consists of six main sections:
* The Power Supply Bay houses two 375 watt power supplies which
provide power to the subsystem.
* The Processor Bay contains the 16-slot passive backplane.
* The Multiplexor/Front Panel permits the subsystem processors
to share a VGA monitor, keyboard, mouse, floppy disk drive, and
reset pushbutton.
* The Drive Bay supports the floppy and hard disk drives.
* The Input/Output Panel provides power entry and signal routing.
* Auxiliary Junction Panels are options which provide mountings
and space for auxiliary I/O adapter boards.
Figure 2-1, Figure 2-2, Figure 2-3, and Figure 2-4 show the front and rear views of the FT Resource Subsystem.
The Cubix FT Resource Subsystem contains two internal 375 watt load sharing, switching power supplies. Each supply is fan cooled. When the power supply load is properly limited to 375 watts average, and the air inlet temperature of the subsystem is maintained between 00C and 400C, the power supply will provide long trouble-free service. Please refer to Appendix B for Power Supply Load Considerations.
Figure 2-5 shows the Fault Tolerant ISA Backplane with 8 groups of 2 slots each (8x2).
Figure 2-6 shows the Fault Tolerant EISA/ISA backplane with one group of 8 EISA slots and four groups of 2 ISA slots each (8E+4x2I). The ISA groups may be connected by shunts.
Figure 2-7 shows the Fault Tolerant EISA/ISA backplane with two groups of 4 EISA slots each and four groups of 2 ISA slots each (4E+4E+4x2I). The ISA groups may be connected with shunts.
Figure 2-8 shows the Fault Tolerant EISA backplane with two groups of 8 EISA slots each (8E+8E).
Figure 2-9 shows the Fault Tolerant EISA backplane with four groups of 4 EISA slots each (4E+4E+4E+4E).
Figure 2-10 shows the Fault Tolerant Server Subsystem which by definition consists of one group of 14 ISA slots and one group of 2 ISA slots (14x2). The groups may be connected with a shunt.
Features of these backplanes are:
* Shunt connectors - between each group of 2 ISA slots are connectors
that permit shunting adjacent groups to form a variety of backplanes
(see Appendix A).
* LED indicators are located at the end of each slot connector
nearest the auxiliary junction panel. Each LED is on when +5vdc
is present on the slot.
* An 8 amp fuse on the +5vdc for each slot provides operator and
externally connected peripheral protection in the event of PCB
failure.
* A Multiplexed floppy drive power connector.
* A LED indicator located near the multiplexed floppy drive fuse.
This LED is on when the +5vdc voltage for the floppy drive is
present.
* A Multiplexed floppy drive power fuse of 8 amps.
* Drive power connectors (quantity 8). These are normally used
to provide power for up to 8 hard disk drives.
* Group Voltage Switches. Relays permit an operator to control
individual group voltages for PCB replacement.
* A Supervisor connector - for Cubix IES System.
The multiplexor muxes the keyboard, video, mouse, reset, and floppy disk drive signals from each Cubix processor to a single set of devices. The keyboard, video, and mouse signals are multiplexed from each Cubix processor to the "Video Out" connector of each ERS/FT Subsystem. The reset signal from each Cubix processor is multiplexed to the reset pushbutton on the front console. The floppy disk drive controller signals from each BC processor are multiplexed into a single shared drive located on the front panel.
Operation of the multiplexor is controlled from the Front Console as described below. Refer to Figure 2-1, FT Resource Subsystem Front Panel.
The "up" and "down" pushbuttons control the selection of up to 8 processors. The "reset" pushbutton is shared among all BC processors. The pushbutton labeled "Enable/Disable" enables and disables the multiplexor.
"Up/Down" Pushbutton
Depressing either of these pushbuttons either increments or decrement the mux by one channel position. Switches mounted on the multiplexor PCB determine the maximum number of enabled processors - one through eight. Therefore, continuously pushing the "up" pushbutton increments the mux to the position associated with the maximum number of processors and then rolls over to display "1". Conversely, continuously pushing the "down" pushbutton decrements the multiplexor selection to "1" and then rolls to the maximum number of enabled processors.
"Enable/Disable" Pushbutton
If the mux is enabled (i.e., a number 1 to 8 is displayed) depressing this pushbutton "DISABLES" the keyboard/video/mouse signals, preventing them from leaving the subsystem, and also disables the reset pushbutton and the multiplexed floppy drive. Depressing this switch again "ENABLES" the mux and connects the video, keyboard, mouse, floppy and reset pushbutton to BC processor Number One. The multiplexor is considered "ENABLED" whenever a port number (1-8) is displayed.
Display
A seven segment display is used. The "O" is used to indicate OFF or Mux "DISABLED". The numbers 1-8 indicate which processor is connected to the video, keyboard, mouse, floppy disk, and reset pushbutton.
Keyswitch
The key switch, when placed in the locked position, disables the multiplexor when all option switches are in the OFF state. Refer to Appendix F for the description of the mux when the option switches are ON.
Power Supply Indicators
The "on-line" and "fault" lights provide an indication of the status of each of the power supplies. Note that if a power supply is not installed, neither the on-line nor the fault light is illuminated.
Group Enable Switch
This eight position switch, mounted on the multiplexor I/O PCB, is used to indicate to the multiplexor which processor positions are active and determines the maximum count. The group enable switch is mounted in an accessible location on the multiplexor so it can be set by factory technicians prior to shipment. It can also be easily changed in the field by a system integrator or end-user, if desired. Refer to Table 2-1 for an example.
If an enabled group either doesn't have a BC processor installed or the group power is turned off, all devices will appear to be disconnected if that group is selected by the multiplexor. For example, selecting a group with it's power turned off will display a blank screen on the monitor.
Note: Enabling any mux in a daisy-chain series of FT Subsystems immediately disconnects all other muxes.
Option Switch
A four position switch mounted adjacent to the group enable switch is used to select the following options:
* Monitor only (when locked, only the monitor is connected)
* Monitor-KB-mouse only (when locked, only the Monitor-KB-Mouse
are connected)
* Floppy/Group 1 (when locked, the floppy is forced to be connected
to Group 1)
* Master keyswitch selection (locking this subsystem will force
all connected subsystems to also be locked)
Appendix F describes the operation of the multiplexor in detail and the effect of the four option switches. It also contains detailed information about the two PCBs comprising the multiplexor.
Group Power Switching
Switches and power-on lights for each group are located under the fan panel inside the Fault Tolerant Resource Subsystem. Powering down an individual group requires a tool (small pen or screwdriver) and turns off all DC power to the slots and hard disk drives associated with that group. There are individual LED's on the backplane near the L-brackets indicating the presence of +5vdc for each slot. The purpose of this is to enable the technician to ensure each slot in a group has power off to prevent the accidental removal of any module with power on.
CAUTION: Disable MUX ("0" displayed) before turning the power off in any group. See chapter 6, Troubleshooting and Preventative Maintenance, for details.
CAUTION: Always place the insulating barrier (Cubix eng no 300-s06710) between the PCB to be removed and an adjacent PCB that still has power on. This insulating barrier is designed to be stored on the left hand side of the subsystem.
The standard disk drive bay in the Resource Subsystem will accommodate either one or two floppy disks and up to nine third-height 3.5" hard disk drives.
An optional disk drive bay capable of supporting up to two 3.5" floppy drives and up to either nine 3.5" TH hard disk drives or up to eighteen 2.5" TH hard disk drives is also available.
Each 2.5" disk support bracket can handle one 3.5" TH drive or two 2.5" hard drives. The 2.5" drives only require one connector each. Both IDE data and +5 volts drive power are routed through one 44-pin 2mm ribbon connector. The cable may be directly connected to Cubix QL 3222 processors.
Each 3.5" TH disk drive requires two connections: one for power and one for data. The disk drives obtain power from connectors on the ISA backplane - nine connectors are supplied. The data cables for each IDE disk drive installed in the subsystem are connected directly to the Cubix processor IDE disk drive controller header located on the top edge of the BC board. The cable is a 40-pin ribbon.
Figure 2-11 shows the connectors on the rear entry panel.
The SUPERVISOR (DsubHD26) connector and cable route the supervisory signals and are identical to the connector and cable used in the Enhanced Resource Subsystem. The VIDEO OUT/VIDEO IN (DB25) connectors and cables route the keyboard, video, and mouse signals into and out of the Fault Tolerant Subsystem and into another subsystem in a daisy-chained fashion.
The two receptacles and AC input switches are associated with each power supply. These receptacles permit separate AC power inputs to each FT power supply.
An optional Auxiliary Junction Panel may be installed in the Cubix Fault Tolerant Subsystem. The Auxiliary Junction Panel is installed in the top rear panel of the subsystem and allows the user to customize solutions for a wide range of I/O requirements.
The Cubix processor boards provide several I/O functions via internal headers. To access the I/O, these headers are connected to an I/O adapter printed circuit board (PCB) installed in an auxiliary junction panel.
Three panels are offered on FT Subsystems. The panel, illustrated in Figure 2-12, provides space to install up to eight DB-25, eight DB-9, and eight Mini-DIN connectors. Typically this panel is used to provide parallel printer, COM2, and mouse support.
An external mouse connector requires disconnecting the mouse cable on the Cubix processor board that goes from the PCB to the Mux. This means, of course, that a shared mouse capability and a direct mouse connection can not be used concurrently.
The panel illustrated in Figure 2-13 provides space to install up to six DB-25, six DB-9, and six Mini-DIN connectors, and two RJ45 modular phone plug connectors. This panel is similar to the one above except that RJ45 I/O for a master supervisory work station is supported.
The panel illustrated in Figure 2-14 provides space to install up to sixteen DB-25 connectors typically used for printer support.
Multiple Fault Tolerant Subsystems can be connected together in a daisy-chained fashion allowing single keyboard, video, and mouse devices to be shared among Fault Tolerant Subsystems.
The Video Out connector of the last subsystem would normally be cabled to the rear panel of the Cubix Cabinet thereby enabling the customer to connect a keyboard, video, and mouse into standard connectors. An interconnection box is also available to break-out the DB25 connector signals into industry standard connectors for VGA monitor, keyboard, and PS/2 mouse.
ERS versus FT Considerations
It is possible for ERS and FT subsystems to share the same monitor, keyboard, and mouse. This requires using the FT video/keyboard mouse interface module and routing the FT monitor/KB/mouse cables to one port of a Cabinet Multiplexor. Using the Cabinet Mux, select either a specific ERS Subsystem or the daisy-chained FT Subsystems.
Supervisor Function
The PA3030 or IES can monitor and control BC processors in both ERS and FT subsystems.
This document, and all Web contents, Copyright © 1997
by Cubix Corp., Carson City, NV, USA.
