Plant status option for CATV power supplies

A Celab product story

Edited by the Electronicstalk editorial team Aug 2, 2001

Celab has released a new interface card for its CATV power supplies, implementing the new industry standard Hybrid Management Sublayer (HMS 022) plant status interface.

Specialist power supply manufacturer Celab has released a new interface card for its CATV power supplies, implementing the new industry standard Hybrid Management Sublayer (HMS 022) plant status interface.

Recognising the importance of this new international standard, and the large installed base of Celab supplies, the new interface has been designed as a simple field-upgrade to existing units, as well as being offered as an option for new CATV power supplies.

For maximum flexibility, Celab's protocol software has been written in C, and the card features a PIC controller, together ensuring that the interface can be easily upgraded to track any future changes in the HMS 022 specification.

The standard enables power supplies and generators to communicate through a non-proprietary transponder protocol to either fibre or coax CATV networks, enabling network operators to integrate equipment from multiple vendors.

Celab has implemented the full HMS 022 protocol, providing both monitoring and control functions for the power supply, its built-in battery management subsystem, and associated batteries.

In addition, Celab's protocol implementation has been optimised to match the timing requirements of Windows-based laptop PCs, which are typically connected locally by on-site maintenance technicians during commissioning or servicing activity.

The Celab card is a direct plug-in alternative to the established analogue and relay-contact card, and not only provides all the local intelligence to respond to status requests and commands, but also delivers the necessary 24V DC 200mA supply to power any HMS-compliant transponder.

The interface uses standard RJ45 connectors to provide the transponder power and the two-wire RS485 communication link, making installation straightforward.

The HMS Interface card enables up to 15 power units to be daisychained to a single transponder, and is ideal for use with supervision systems based on SNMP, especially when implementing an SNMP v1 MIB (Management Information Base).