GAI-Tronics 69440-001 Master Control Unit PCBA (MCU) - Manual (Page 2)

Pub. 42004-676L2B
Model 69440-001 Master Control Unit PCBA Page: 2 of 8
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These LEDs are ON, they have the following meanings:
LED Description (When ON)
-12V The card rack is providing –12 volts dc to the MCU.
+12V The card rack is providing +12 volts dc to the MCU.
+5V The card rack is providing +5 volts dc to the MCU.
BEEP This LED simulates the CPU module speaker function. The LED emits light instead of a
speaker emitting sound..
N OTE 1: The LED flashes ON briefly when the PC begins booting, otherwise, this LED
is OFF. If applicable, your system manual lists situations where this LED should be ON.
N OTE 2: If the CPU Module detects an error during boot-up, this LED will flash more
than once. In this error condition, the CPU Module generates, a one-time “beep code” to
aid in diagnosing the fault. Momentarily pressing the reset button will cause the beep
code to repeat.
LINK Shows Ethernet network status. The MCU has established a communications link with
another Ethernet network device.
ACT Shows Ethernet network status. The MCU detects activity on the attached Ethernet
cable.
BP The MCU is using the data bus in the card rack.
The card rack is sometimes referred to as “back plane,” which gives this LED its
abbreviation (BP).
SPD This LED operates in conjunction with LINK LED to indicate the speed of the Ethernet
network connection.
LINK (On) SPD (Off) = 10 MB Ethernet connection
LINK (On) SPD (On) = 100 MB Ethernet connection
LINK (Off) SPD (On) = no network connection established
SEC The MCU is accessing the Compact Flash card connected to the secondary IDE
controller.
PRI The MCU is accessing the hard disk drive connected to the primary IDE controller.
B7, B6, B5,
B4, B3, B2,
B1, or B0
These LEDS are referred to as the Port 80 LEDS. They are used to show diagnostic
information that can be used by factory trained technicians as a troubleshooting aid.
MCU Front Panel Connections
The PS/2 keyboard and PS/2 mouse connectors enable connecting a PS/2 keyboard and a PS/2 mouse,
respectively, to the MCU. These connectors are color-coded to match the PC99 standard. In order for the
mouse to function properly, it must be connected at power-up.
The COM2 RS232 port provides a RS232 serial connection to the MCU. This connector’s pin-out
matches that of a standard PC’s 9-pin serial connector pin-out.
N
OTE : The COM2 RS232 port is logically in parallel with the COM2 RS485 half-duplex port on the rear
of the card rack; therefore, both of the ports may not be used simultaneously.