sle 2.2.5

CCSDS Space Link Extension (SLE) Protocol

Python SLE

Implementation of the CCSDS Space Link Extension (SLE) API in Python. It provides the RAF (Return All Frames) and RCF (Return Channel Frames) Return Link Services and the CLTU Forward Link Service.

The CCSDS Space Link Extension (SLE) services are used by all major space agencies to interconnect ground stations to mission control systems. The SLE is a standardized protocol that enable such cross-support. In basic terms, a groundstation communicates with a spacecraft through CCSDS telecommand and telemetry frames. The transfer of those frames between a groundstation and a remote mission control system is done via SLE, which is essentially just a container protocol that runs over TCP/IP. On the side of the groundstation there sits a SLE provider gateway and on the mission control side there is a SLE user gateway.

This Python package implements the SLE User API and can be used to develop SLE user and provider gateway applications on top of it.

Installation

Install via pip:

$ pip install sle

Example

To create a service for receiving all return frames, we create a RAF User. Then we bind to the remote SLE Provider and start the reception of frames.

import time
import sle

raf_service = sle.RaServiceUser(
    service_instance_identifier=SI_IDENTIFIER,
    responder_host=RESPONDER_HOST,
    responder_port=RESPONDER_PORT,
    auth_level="bind",  # or "all" or None
    local_identifier=LOCAL_IDENTIFIER,
    peer_identifier=PEER_IDENTIFIER,
    local_password=LOCAL_PASSWORD,
    peer_password=PEER_PASSWORD)


def print_frame(frame):
    print(frame)


raf_service.frame_indication = print_frame

raf_service.bind()
time.sleep(1)
raf_service.start()
input("Press <Enter> to stop")
raf_service.stop()
time.sleep(1)
raf_service.unbind()
time.sleep(1)

Documentation

The API documentation is in docs/README.md. The user manual for pyasn1 is at this address.

Contribute

• Issue Tracker: https://gitlab.com/librecube/lib/python-sle/-/issues
• Source Code: https://gitlab.com/librecube/lib/python-sle

To learn more on how to successfully contribute please read the contributing information in the LibreCube guidelines.

Support

If you are having issues, please let us know. Reach us at Matrix or via Email.

License

The project is licensed under the MIT license. See the LICENSE file for details.