User's Manual

Table Of Contents
Unit Descriptions - RF Path CMA-331-AEN Page 34
Draft
2.1.1 HEU (Headend Unit)
The HEU performs the following main functions:
Conditions (up to 12) RF sources to a level required for feeding to the Optical Interface Unit (OIM).
Enables the configuration of up to three sectors consisting of groups of RF services.
Main HEU includes HCM module enabling single source control and management of the ONEsolution RF path
Auxiliary HEU includes ACM modules and is managed via the HCM in the Main HEU
Note: Only one HEU per system can be installed with an HCM module and serves as the “Main HEU”. Any additional HEU
chassis are installed with ACM modules and are considered “Auxiliary HEUs”.
Each HEU supports up to 12 services. For additional services or density, two or more HEU units can be cascaded so that the
Auxiliary HEUs are managed from the Main HEU (via the HCM). For HEU installation procedure, see section 5.1.1.
Figure 2-3. HEU Front Panel with Installed Modules
HEU hosts the following modules:
Module Description
HCM (Headend Control Module)
Provides overall system management and control functions. The
HEU in which the HCM is installed serves as the Main HEU. See
section
2.1.1.1.
ACM (Auxiliary Control Module)
Provides interfaces for management of domestic modules via HCM;
Installed in HEUs’ in configurations with more than one HEU; HEU
chassis with ACM modules are considered Auxiliary HEUs. See
section
2.1.1.2.
RIM (RF Interface Module)
RF source conditioner; Provides the service specific RF interface to
the RF source; Up to 12 RIMs can be hosted by the HEU; See
section
2.1.1.3.
RIX (RF Expander Module)
HEU to OIU interface module; See section
2.1.1.4.
ETM (Expander Termination
Module)
For configurations with one RIX an ETM is required for terminating
the unused Expander slot. See section
2.1.1.5.
PSM (Power Supply Modules) PSM-AC:100 - 240 V AC