Cabletron Systems MRXI-22 User Manual

Contents

TESTING AND TROUBLESHOOTING4-6LNK (Green)When this LED is lit, it indicates an established link between theassociated twisted pair segment and the 10BASE-T device at the otherend of the segment. This LED will remain lit as long as a link ismaintainedIf a port receives no data for 16 msec from the device at the other endof the segment, a positive link test pulse of 100 nsec is sent onto thetransmit link of the twisted pair cable. The MRXI receives these linktest pulses and checks to determine if they occur at the correct rate,polarity, and pulse shape. If the MRXI receives no link test pulses, orthe pulses are not correct, the transceiver enters the Link Fail State andthe LED will not be lit. The MRXI does not receive or transmit datauntil it receives a correct link test pulse or a valid packet.When the MRXI is powered-on, the LNK LED flashes if the MRXIdetects reversed polarity on the segment attached to the associatedport.CPU (Flashing Green)This LED alternates from red to green during power up. After the bootis complete, the LED flashes green. A flashing green LED indicatesnormal operation. A red LED indicates a faulty processor.4.4 THE LCD DISPLAYThe MRXI is equipped with an LCD display as shown in Figure 4-3. TheLCD display is a diagnostic tool that gives you important statusinformation about the MRXI such as: Power up diagnostics, Revisionlevels, MAC and IP Addresses, and Error Alerts.