Reliant Octel 200 and Octel 300 Message Servers PB6001401 - Manual (Page 95)

Hardware 2-23
Octel Overture 200/300 Serenade 3.0 PB60014–01
The PSU provides regulated d.c. voltages. The voltages are shown in Table 2-4.
Table 2-4 Power Supply Unit d.c. Voltages
Name Nominal d.c. Voltage Function
+5 V 5 volts
Digital logic power
+5 VC 5 volts
Analog circuit power
+12 VM 12 volts
Fan and disk drive motor power
+12 VC 12 volts
Analog circuit power
ć12 VC ć12 volts
Analog circuit power
ć5 VC ć5 volts
Analog circuit power
The PSU provides the system power fail signal. This signal is activated if the message-server input
voltage drops out of operational range. The power fail signal interrupts the CPU as a warning of loss
of primary power, allowing controlled shutdown of the Octel Overture 200/300.
On the Octel Overture 200, the PSU provides a protective fuse for primary power production. This
fuse is opened when a primary overcurrent occurs. The PSU contains a spare fuse.
On the Octel Overture 200, the +5-volt PSU is sensed at the center of the motherboard. Each
regulated voltage of the PSU includes overvoltage and overcurrent protection. The PSU also includes
overtemperature protection.
On the Octel Overture 300, the PSU provides the message server reset signal. This signal is activated
at power up and resets all boards in the message server. The PSU provides a protective circuit breaker
for primary power. This circuit breaker also acts as the message server power switch. The circuit
breaker is tripped for primary overcurrent, power supply overtemperature, and secondary overvoltage.
On the Octel Overture 300, the +5-volt PSU is sensed at the center of the shelf A motherboard. The
+12-volt fan and drive motor power is sensed at the SCSI motherboard B and SCSI motherboard C.
Each regulated voltage of the PSU includes overvoltage and overcurrent. The PSU also includes
overtemperature protection. In the case of an overtemperature occurrence, the circuit breaker opens.
Motherboard
The Octel Overture 200 has one motherboard. The Octel Overture 300 has three motherboards, one
each for shelves A, B, and C.
Octel Overture 200/300 Motherboard
The motherboard is installed in the rear of the cabinet and distributes d.c. power to the cards, disks,
and fans.
The motherboard includes signal interconnections from slots A1 through A7 on shelf A to the rear
connectors P1 through P7, respectively. These connectors are used for external circuit connections to
cards installed in the respective slots. For example, a line card installed in slot A1 connects to
tip-and-ring circuits of a telephone network through rear connector P1.