Specifications

The front panel of the PCI-Short-Card interface pictured above is the vertical metal plate on the

left-hand side of the interface. Two LEDs and the cable connector penetrate this PCI front panel

(also known as a face plate).

For the PCI mezzanine cards (pictured below), the two LEDs are on either side of the SAN cable

connector.

PCI64B PMC interface

The LEDs have the same functions for PCI-Short-Card (PCI) and PCI-Mezzanine-Card (PMC)

interfaces.

For Fiber (M3F) and Serial (M3S) interfaces, the green “link” LED will illuminate when the

board is powered, the firmware (such as the GM Myrinet Control Program) is loaded, and the

link is active. These conditions are satisfied by a port being plugged through a cable to a

powered switch, to another initialized interface or to a loopback plug. The green LED blinks at

up to ~5Hz to show when packet traffic is flowing through the port. The green LEDs on

Myrinet-2000 switches operate similarly.

For Myrinet-SAN (M2M/M3M) interfaces, the behavior of the green “link” LED is the same as

for Fiber and Serial ports if the high-availability (HA) features are enabled in the MCP. (The

LED operates from the detection of link continuity using the presence of the HA BEAT control

symbol on the link.) If the HA features are disabled, the link LED of a SAN port will be on even

without a cable or loopback plug connected to the port.

The yellow “LANai” LED is controlled by the LANai processor, and its meaning may be

different for different Myrinet Control Programs. For the GM MCP, the yellow LED will pulse

like a heartbeat while the MCP is running, and will pulse faster when there is more packet-

sending activity (including sending acknowledge packets in reply to packets received.) If the

yellow LED is not pulsing, the GM MCP is not loaded or is not running.

It is safe electrically to plug or unplug the interface from the switch while the host is powered on.

However, if you unplug the cable and plug it into another port on the switch or into a different

Green LED

SAN connector

Yellow LED

PCI Mezzanine

connectors