Workpackage: Communication/Logical Protocol

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

Leader: Bernhard Tittelbach <xro AT realraum DOT at>

Telemetry Protocol Specification revision 249

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


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

- using CW on FSK
- 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)

• Battery-voltage
• Temperature
• Solarcells-voltage
• RTC Time
• RX/TX Receiver status
• RX/TX number of queued commands
• current Energy Token Value