About MIL-1553 Front-End


The MIL-1553 Front End is an EGSE unit to control, monitor and simulate flight equipment on the satellite onboard data handling bus during the spacecraft development, assembly, integration and test (AIT) phases.

In a typical application, the MIL-1553 Front End is used as Bus Controller (BC) to test one (or multiple) Remote Terminals (RTs), by simulating the spacecraft specific 1553 protocol, including TM/TC transfer mechanisms. With a different software configuration, the same hardware can be used to simulate up to 31 Remote Terminal(s).

An optional 1553 interface channel can be added to provide a fully independent 1553 Bus Monitor (BM) with sophisticated filter, archiving and export functions to analyse the (dual redundant) spacecraft MIL-STD 1553B bus.

MIL-1553 Front-End back
MIL-1553 Front-End front

Click image to enlarge

Key Features


  • Supports multiple MIL-STD-1553B functions in a single platform:
    • Bus Controller
    • Remote Terminal (simulator)
    • Bus Monitor
  • Scheduled cyclic and non-cyclic 1553 bus operations based on user-defined input
  • 1553 bus operations synchronised to external input(s)
  • Major frame synchronisation to Pulse per Second signal (internal or external)
  • Configurable minor frame interval (e.g. 125, 50 and 12.5ms)
  • Supports Data Block Transfer Service as described in ECSS‐E‐ST‐50‐13C
  • Sophisticated error detection/injection, statistics, logging, and data archiving
  • To be used stand-alone or remotely via Central Checkout System (CCS)
  • FMEA report available
  • Bus couplers, cables and terminators can be supplied

Key Features


  • Supports multiple MIL-STD-1553B functions in a single platform;
    • Bus Controller
    • Remote Terminal (simulator)
    • Bus Monitor
  • Scheduled cyclic and non-cyclic 1553 bus operations based on user-defined input
  • 1553 bus operations synchronized to external input(s)
  • Major frame synchronization to Pulse per Second signal (internal or external)
  • Configurable minor frame interval (e.g. 125, 50 and 12.5ms)
  • Supports Data Block Transfer Service as described in ECSS‐E‐ST‐50‐13C
  • Sophisticated error detection/injection, statistics, logging, and data archiving
  • To be used stand-alone or remotely via Central Checkout System (CCS)
  • FMEA report available
  • Bus couplers, cables and terminators can be supplied

The system consists of a 19” 2U hardware platform, connected to the C-STS Control and Monitoring Software (CMS). The system is used as a desktop connected with a standard PC or integrated into a 19″ rack.

The MIL-1553 Front-End operates as the electrical interface (through commercial MIL-1553 bus coupler) towards flight equipment and provides data extraction, protocol handling, and status annotation functions. The unit itself is powered from an external AC/DC adaptor.

As a Bus Controller (BC), the MIL-1553 Front-End implements a periodic, deterministic Mil-Bus scheduler. This supports synchronous and asynchronous data transfers. The 1553 message scheduler is based on a standard text file enabling the user to, on-the-fly, modify the (simulated onboard) bus profile. The major and minor frame 1553 bus timing is synchronized to an external signal (e.g. Pulse Per Second) and is highly configurable to take into account the satellite specific message slot timing.

Standard Bus Controller functions include; Bus A/B switching, programmable timing parameters for ‘No-response timeout’ and Inter-Message Gap (IMG), RT Ignore, FDIR Enable/Disable as well as error detection and injection. As an option the Bus Controller functionality can be extended with a protocol-specific Dynamic Link Library (DLL) to support, for example, the Data Block Transfer or Time Distribution services (ECSS-E-ST-50-13C).

Standard Remote Terminal functions include; Remote Terminal Enable/Disable, Bus A/B switching, programmable timing parameters for ‘RT-response time’ and user programmable mode code response words, as well as bit-based Status and Data word corruption.

Dedicated functions are available for reading and writing/configuring the sub-address content of simulated Remote Terminal(s) independently.

The fully independent, Bus Monitor (BM) is controlled through dedicated software that enables the user to monitor the traffic (including time-stamps) on a redundant 1553 bus. Sophisticated filters can be applied to trigger on (and capture) specific bus conditions. Near real-time data analysis can be performed, while continuous storing all 1553 traffic to disk in parallel. Off-line data analysis of previously recorded sessions can be performed with the same GUI. For data analysis, an export function is available that supports various output formats. Optionally, the Bus Monitor function can be equipped with project-specific decoder DLL, to support textual decodes and user-specific color schemes (simplifying 1553 data analysis).

C-STS have delivered MIL-STD-1553B systems for more than 20 years to all major European prime contractors such as AIRBUS, THALES and OHB to support ESA and non-ESA spacecraft missions including Herschel, Planck, Aeolus, Mars Express, Galileo, Gaia, Bepi Colombo, Sentinel (1, 2, 3 and 6), EarthCARE, Solar Orbiter, ExoMars (2016 and 2020), JUICE, EUCLID (2019).