 |
|
|
|
FT
Subsystems
Chapter 3 - Server Subsystem
Overview
Power Supply
Processor Bay
Multiplexor/Front Panel
Drive Bay
Input/Output
Auxiliary Junction Panels
System Considerations
The Cubix Fault Tolerant (FT) Server 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 3-1 and Figure 3-2 show the front and rear views of the FT Server Subsystem.
The Cubix FT Server 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 3-3 shows the Fault Tolerant 14+2 ISA Backplane.
Features of these backplanes are:
* Between slots 14 and 15 on 400-A04090 is a connector that permits
shunting together groups 1 and 2 to form a contiguous 16 slot
ISA backplane. (Shunt board, #A3900 is normally installed in
this connector.)
* 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 protection
for the operator and external peripherals 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 9). These are normally used
to provide power for up to 9 hard disk drives.
* A Supervisor connector - for Cubix IES use.
Usually the server will only have a single processor installed. (An exception might be a single BC processor with multiple QL processors.) Therefore, the devices (video, keyboard, mouse, floppy and reset pushbutton) normally shared among multiple processors in a FT Resource Subsystem will be dedicated to the single processor in this FT Server Subsystem. Operation of the multiplexor in a single processor subsystem is very straightforward: depress the Enable/Disable pushbutton to select and deselect Group 1. With the Group Enable Switch set with only 1 active group, the Up/Down pushbuttons have no effect.
For a more detailed explanation of the multiplexor, refer to the following section and to Appendix F.
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 3-1, FT Server 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 decrements 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
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. 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. Refer to Table 3-1 for an example.
If an enabled group doesn't have a BC processor installed, all devices will appear to be disconnected if that group is selected by the multiplexor. For example, selecting an unconnected group will display a blank screen on the monitor.
F 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.
The drive bay in the Cubix Server Subsystem will accommodate up to four half-height or four third-height 3.5" hard disk drives, one half-height 3.5" tape drive, and one third-height 3.5" floppy disk drive.
Each drive requires two connections: one for power and one for data. The 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 from each drive 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 flat ribbon cable.
An optional disk drive bay capable of supporting one half-height 3.5" HH tape drive, one 3.5" floppy drive, and up to either four 3.5" TH or HH hard disk drives, or up to eight 2.5" TH hard disk drives is also available.
Each 2.5" disk support bracket can handle one 3.5" TH or HH 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. A conversion board and 40-pin IDE ribbon cable is required to directly connect a 2.5" IDE drive to a Cubix BC processor.
Figure 3-4 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.
Optional Auxiliary Junction Panels 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.
The panel, illustrated in Figure 3-5, 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.
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 mux break-out 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.
