Chapter 8: Downstream Cable Access Modules (DCAMs)
STANDARD Revision 1.0
C4® CMTS Release 8.3 User Guide
© 2016 ARRIS Enterprises LLC. All Rights Reserved.
237
Table 27.
XD Cable Access Module LED Descriptions
Front LEDs
Module Status
Power
Out of
Service
On
Off
Powered and in normal service state
Flashing
On
Flashing = 1.6 second period. Module power is off: either slot is not provisioned or
module has been disabled.
Persistent
Fast
Flashing
On
Fast flashing = 6 times/second. Normal when card is first powered or restored. If fast
flashing persists for more than 2 seconds, there is a serious power problem.
On
On
Powered and out of service.
On
Flashing
Downloading data from SCM, initializing or running diagnostics.
Off
Off
The slot has no power.
QAM Modulation Order and Port Requirements
The XD CAM supports:
64QAM and 256QAM operation
A unique setting of 64QAM or 256QAM per F-connector of the 16D CAM PIC.
Each F-connector of the 16D CAM PIC can be set to 64QAM or 256QAM mode independent of the other F-connectors.
Any change to the modulation will change the modulation of all channels on that F-connector.
Spectrum Window and Frequency Grid for Channels on the Same F-connector
Downstream channel frequencies assigned to the same F-connector are required to occupy a limited number of slots of a
frequency grid. For example, a 6 MHz grid would be used (in most cases) for an Annex B card. The size of the spectrum
window (i.e. the total number of slots) is limited by the passband of the analog filters used in the RF upconverters; in the
case of the 16D and XD CAM cards, this is 80 MHz. This is illustrated in the figure below.