Workpackage: Communication/Logical Protocol

This page contains information about the Technical Workpackage Communication/Logical Protocol

Leader: Bernhard Tittelbach

Telemetry Protocol Specification revision 249

Protocol Definition for TTX Beacon to Ground Stations
=====================================================


Introduction
------------

- using CW
- transceiver should send a beacon about every 60s
- transceiver sends acknowledge frame if requested
- parity 

Signs (Char Table)
------------------

!"$&'()+
,-./0123
456789:;
<=>?@ABC
DEFGHIJK
LMNOPQRS
TUVWXYZ

Base32 Coded Signs
------------------

   | 0 1 2 3 4 5 6 7 8 9 A B C D E F
-------------------------------------
00 | A B C D E F G H I J K L M N O P
10 | Q R S T U V W X Y Z 2 3 4 5 6 7

Beacon Frame:
-------------

'N'       (1 Sign)   .. Start Character (-.)
CALLSIGN  (4 Signs)  .. the satellites call sign (i.e. OE0M)
CNT       (3 Signs)  .. beacon counter (Base32)
STATE     (1 Sign)   .. Base32 coded bitfield
CMDQLEN   (1 Sign)   .. Number of commands in queue (Base32)
... tba
CHECKSUM  (1 Sign)   .. Parity Sign


 Bitfields
 ~~~~~~~~~

  STATE:

  LSB     RX_STATE   .. Payload Receiver State (0 = OFF, 1 = ON)
  ... tba
  MSB    

Acknowledge Frame
----------------

'A'       (1 Sign)   .. Start Character (.-)
CRXCODE   (1 Sign)   .. unscrambled command code from CRX
CHECKSUM  (1 Sign)   .. Parity Sign

Additional information possibly to be included in telemetry beacon:
(depending on final duration of beacon versus contact window duration)

Battery1-voltage
Battery2-voltage
Temperature for each sensor
Solarcell-voltage separately for each of 8 solarcell panels
Solcarcel-Volate (mean of all voltages)
RX/TX receiver status
current EnergyTokenValue

possibly take some pages out of XW-1 Telemetry Format, especially number encoding.

Final equations of numerical values to be published on finalization of electrical systems design.