9.0 Start Up and Verification, continued
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704-939-B10-001 Rev. A5 (06/2019)
9.3.1 Detailed LED Descriptions
After power is applied or a reset occurs, all LEDs will flash in certain patterns indicating the cable modem chipset is
starting or restarting. Once it is ready, it will begin the DOCSIS requirement of searching for the downstream frequency
lock and the LEDs will follow the detailed descriptions below.
ALM/RDY - Alarm/Ready
During normal operation, this LED blinks GREEN, indicating a heartbeat pulse from the processor. The frequency of
flashing by this LED provides a visual alert for power supply discrete major and minor alarms, if configured in the property
and discrete property tables of the SCTE-HMS MIB. The ALM LED (RED) is factory defaulted OFF. Refer to Section
6.2.3, General Power Supply Alarms for information on configuring the DM3X Transponder for active monitoring and
alarming. If an event triggers an HMS alarm, the ALM/RDY LED blinks RED according to the alarm type until the alarm
has been resolved. For a minor alarm, the frequency of flashing (RED) will be more OFF than ON and for a major alarm
the frequency of flashing will be (RED) more ON than OFF. If there are multiple active alarms, including one or more major
alarms with one or more minor alarms, the major alarm will take precedence in terms of the indication.
DS - Downstream Communication
This LED indicates the state of the CM’s attempt to gain a downstream signal. This process may take several seconds,
depending on how long it takes the CM to locate a carrier signal and lock onto a channel. The LED flashes while
searching for the downstream DOCSIS channel and is on solid when the downstream channel is locked.
US - CM Registration
Once a downstream channel has been negotiated between the CM and CMTS, the modem attempts to register with the
DHCP server and obtain the Configuration File. This LED flashes while the process takes place. Once a ranging status of
‘success’ has been received, the LED will remain on solid. This is the best indication that the DM3.0 Series Transponder is
communicating with the CMTS in the headend.
OL - Network Communication Status
The Ethernet link LED remains ON when there is an active connection on the Ethernet port (e.g., a computer is connected
for local diagnostics). Momentary flashes during CPE communications via the Ethernet Craft Port when connected to a
CPE device OR flashes while performing early authentication, IP connectivity, BPI initialization.
LNK - CPE Activity
The CPE activity LED flashes to indicate that data is being transmitted or received between the DM3.0 Series
Transponder and a network device.
