Troubleshooting guide
MX2820 System Manual
1-8 61186003L1-1D
The MX2820 SCU provides the following features:
• Manages RJ-45 10/100Base-T Ethernet port for SNMP, TFTP, Telnet, and SSH access
• Interbank communications capability to address multiple shelves with a single IP via an
RS-485 daisy chain communication link between shelves
• One IP address per shelf
• X.25 capability for TL1 sessions
• Four simultaneous Telnet or SSH logins
• Manages DB-9 RS-232 interface for an asynchronous craft interface
• Supports flash upgrades via TFTP and YModem
• Displays Activity (ACT) and Alarm (ALM) status via front panel LEDs
• Maintains system alarm logs
• Allows manual suppression of active alarms by pressing the front panel Alarm Cutoff (ACO)
switch
• Supports three auxiliary inputs from wire-wrap posts on the backplane
• Supports cadenced alarm signal from the MX2820 fan unit on AUX3 input
• Power A/B detection
• Controls common, normally open, and normally closed relay contacts for Critical, Major,
and Minor alarms
• NEBS Level 3, UL 60950, GR-1089-CORE compliant
• Operates over temperature range of –40°C to +50°C (no fans), –40°C to +65°C (with fans)
• Derives power from redundant VDC supplied to the shelf
SCU Front Panel LEDs
Table 1-1 provides a description of each LED state for the SCU.
Table 1-1. MX2820 SCU LED Descriptions
LED State Description
ACT
Solid Green
Alternating Green/Amber
Solid Red
Solid Amber
Alternating Red/Amber
Flashing Red
Everything is OK and operating normally
Everything is OK and console is open
Self-test failed
Software update is in progress
Self-test failed and console is open
SCU Module has failed
ALM
Solid Green
Flashing Red
Solid Red
Flashing Amber
Solid Amber
No critical, major, or minor alarms in progress
Critical alarm in progress
Major or minor alarm in progress
Critical alarm was highest priority alarm suppressed by
ACO
Major or minor alarm was highest priority alarm sup-
pressed by ACO