CCSDS/ECSS Telemetry and Telecommand EGSE

The CCSDS / ECSS Telemetry and Telecommand EGSE (Electrical Ground Support Equipment) provides the necessary means for communicating with the on-board space segment. It has been designed to support satellite integration and test activities, on-board space segment development, ground segment applications, etc.

The EGSE communicates directly with the on-board telemetry encoder and telecommand decoder devices, TM/TC boards and units, bypassing the transponder. The EGSE is ideally suited for the verification of FPGA designs and validation of ASIC devices, as well as during integration of complete TM/TC boards or communication subsystems.

The TM/TC EGSE comprises two parts: a generic hardware implementing the lower CCSDS / ECSS protocol levels; and advanced software implementing the higher CCSDS / ECSS protocol levels. The TM/TC EGSE is fully compliant with the latest CCSDS recommendations and ECSS standards. The TM/TC EGSE is also compatible with the Reference Avionics System Testbed Activity (RASTA).


The TM/TC EGSE hardware establishes the link between the on-board flight segment and the ground segment software. The EGSE features standardized RS422 interfaces supporting up to 10 MBPS transfers on the downlink and up to 1 MBPS on the uplink. The EGSE hardware communicates with the ground segment software through a 10/100 Mbit/s Ethernet interfaces via TCP/IP.


The TM/TC EGSE hardware is based on Cobham Gaisler’s GRTMRX and GRTCTX IP cores.  

Telecommand transmitter capabilities:

  • Frame Error Control Field (FECF)
  • Pseudo-Randomizer (PSR)
  • Bit Transition Generator (BTG)
  • Communications Link Transmission Unit (CLTU)
  • Start Sequence insertion
  • Bose-Chaudhuri-Hocquenghem (BCH)
  • Tail Sequence insertion
  • Physical Layer Operations Procedures (PLOP-1, PLOP-2)
  • Non-Return-to-Zero Mark/Level (NRZ-M/L)

Telemetry receiver capabilities:

  • Operation Control Field (OCF) extraction
  • Frame Error Control Field (FECF) calculation
  • Pseudo-De-Randomizer (PSR)
  • Attached Sync Marker search (ASM) 
  • Non-Return-to-Zero Mark/Level (NRZ-M/L)
  • Convolutional Quick-Look Decoder
  • Split-Phase Level de-modulator (SP-L)
  • Sub-Carrier de-modulator (auto-detection)

The EGSE hardware can communicate with the library of CCSDS/ECSS routines described below. 

Note that the RAMSES (Rocket and Multi-Satellite EMCS Software) software has been discontinued. TM/TC EGSE hardware is instead delivered with the CCSDS/ECSS library described below.

CCSDS/ECSS library

The CCSDS/ECSS library provides basic routines for generating uplink commands and checking downlink data. It is delivered in source code, together with example applications operating on ASCII files.