Silicon Graphics Origin200, Owner'S Manual

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Chapter 2: Setting Up an Origin200 System
Connecting Two Origin200 Modules
When you connect two Origin200 modules together using a CrayLink cable, one module
becomes the master and the other becomes the slave. This relationship is set by a DIP
switch located on the module system controllers (MSC) of each chassis, and has the
following features:
• Only the master module can have a system console.
• The master module controls the power-on and power-off sequence.
• You can communicate with the module system controller (through the AUX port) in
the master, but not in the slave module.
• Both master and slave modules must have memory (DIMMs) installed in them.
• The slave module does not require any disk drives.
When connecting power to the two modules, you may use different electrical circuits
(circuits protected by individual fuses or breakers). However, both circuits must be
connected to the same grounded power source (service entrance or breaker box).
Caution: If the chassis are not connected to the same grounded power supply, resulting
differences in ground potential (current) can damage components on the Origin200 main
system board.