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).

Hardware 

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 either communicate with a complete GUI based ground station software called RAMSES, or with a library of simple CCSDS/ECSS routines. 

RAMSES

The RAMSES (Rocket and Multi-Satellite EMCS Software) is a new generation general control system that includes the core functionality of a mission control system while offering great advantages compared to other control systems available on the market. The system can be applied to both satellite and sounding rocket missions and is designed to be used during the development, integration, validation, and operational phases, thereby significantly decreasing project costs. RAMSES has been developed by the Swedish Space Corporation (SSC).

Only supported on Windows XP.

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.

Documentation

• TM/TC EGSE Product Sheet