FT2400 'Plexus' Buckeye Motherboard Layout (Rev 1.14)

Front View

Rear View

Motherboard

1	Parallel port (LPT)	15	HDD activity - J40
2	Ribbon connector for COM2	16	Jumpers/options
3	Power	17	Fan 2, bottom front
4	Auxiliary power	18	CMOS battery
5	Front panel	19	Server management port
6	Floppy drive port	20	ISA bus card slots
7	SCSI	21	PCI bus card slots
8	Fan 1, primary roof	22	Network status LEDs
9	Fan 3, secondary roof	23	Video memory upgrade
10	Fan 4, middle roof	24	Keyboard and mouse ports
11	I2C - J45	25	Video
12	IDE	26	Serial port (COM1)
13	Processor/Memory board socket	27	Ethernet port
14	Speaker

Processor and Memory Module

Memory

The memory is configured from 8 DIMM sockets supporting ECC. A single DIMM socket is a single memory bank. Memory banks can be populated with any size of DIMM, banks should be filled in ascending order. Single bit error correction and multi bit error detection is done by the memory controller. DIMM types 32MB, 64MB, and 128MB DIMMS are supported. Memory is detected automatically from the BIOS , no jumpers are required. Maximum system memory is therefore 2GB.

Note: Micron 256MB DIMMS do not fit within the chassis , suggested limitation to 128MB DIMMS.

Sample DIMM size configurations

Front Panel Controller

Hot Swap Backplane

The chassis contains provision for 2 off 5 slot hot swap backplanes. These can support only 1inch high SCA II drives. The backplanes can support up to Ultra Wide data transfers of 40Mb/sec. On each backplane is a SAF-TE / I²C controller. This allows the system to detect drive insertions and removals as they happen to the system. Control of the system is primarily through the I²C bus . LED control is also achieved through the I²C bus and microcontroller. The controller needs to be initialised to drive the front panel. The SAF-TE target is always set to SCSI ID 6.

Jumper Options

The drive ID’s are set by the backplane according to the settings of the J9 and J10 jumpers and the following table.

SCSI BIOS’s should be set to spin up drives as the backplane does not implement this function.

The SAF-TE target should support the following notifications
PSU failures - only if the load sharing backplane is installed
Fan Failures
Drive removals and insertions - only if AMI card fitted.

Note that it is the responsibility of the SAF-TE device to spin up drives during operation of the system.

Note installation of second backplane requires power and control cables to be connected to the PSU and front panel board respectively.

Power Distribution

Power

The power sub system of the system is supplied in 2 configurations. 1) Non load sharing and 2) Load sharing ( in redundant and non redundant configurations)

1) Non Load sharing
In this configuration a single PSU is connected to an internal wiring harness through the Molex connection. This then supplies power to motherboard and disk sub systems. The control connection from the PSU connects directly to the motherboard. This control connector contains voltage remote sense lines, 5V Standby, Power On and Power Good signals.

In this configuration the maximum systems configuration is limited to 300 Watts. This configuration is known as "Half Load" - which limits the machine to supporting a maximum configuration of 5 Hard Disk Drives, 2 CPU's, and 512MB.

2) Load Sharing
In this configuration the same PSU is connected to a load sharing PCB in the product. This has provision for up to 3 PSU’s. From the Load sharing PCB connections are made to the motherboard and drive sub systems. The maximum systems configuration is dependent on the amount of PSU's present in the system. This configuration can either be redundant or not. In order to be redundant then there must be 1 more PSU than the system needs to power the configuration. These limits can be found by inputting the configuration of the system into the power spreadsheet.

PSU Power

Each PSU ( Delta DPS333AB rev S3.P/N: 658841-004 ) is cable of the following power limits from AC voltages 100 to 120Vac and 200 - 240Vac dependent on switch selection of PSU ( 50 to 60 Hz).

Each PSU produces a 0.1A standby power which supplies to the management microcontrollers. PSU are controlled so that they can be soft started by the system dynamically during operation of the system. Further the maximum power output is actively limited to 240VA. Through the I2C bus The current levels in each output can be measured. Each PSU will also indicate failure and presence to the load sharing board.

If a second power supply is fitted it will be fitted in the bottom PSU position inside the chassis. If a third PSU is fitted it will replace the fan that was fitted in the middle PSU position.

Cooling

In non load sharing configurations the PSU provides cooling with an additional fan at the middle PSU addition site. These fans are connected back to the SCSI backplanes for instrumentation.

Two fans will be fitted in the machine unless configured for redundancy, then an additional 2 fans will be installed.

Add-Ins

Hard Drives

Tape Drives

Floppy Drives

CD-ROM

Jumper Settings

CMOS

The jumper on J43A pins 1 and 2 preserves the CMOS settings during system reset. Moving the jumper to pins 2 and 3 clears CMOS and sets it and the real-time clock (RTC) to the manufacturing default settings during system reset.

To reset the system’s CMOS and the RTC to factory default values:

Remove the left side cover.
Move the jumper on J43A from pins 1 and 2 to pins 2 and 3; replace the left side cover, and connect the power cable(s) to the system.
Turn the system on, and wait for POST to complete. This automatically reprograms CMOS and RTC to their default settings.
Turn the system off, disconnect the power cable(s) from the system, and remove the left side cover again.
Move the jumper on J43A from pins 2 and 3 to pins 1 and 2; replace the left side cover, and connect the power cable(s) to the system.
Run the SCU to configure your system.

System Resources

I/O Map

*SCSI I/O base address is set using the configuration registers.

Interrupts

The following signals will be rerouted to the above interrupts:

POST Beep Codes