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CAS300 – Serial and USB protocol used by Classpad 300 / 330 (+)

The CAS300 protocol is a variation of CAS50 and CAS100 specific to the Classpad 300 / 330 (+), used over USB and serial links between 2003 and 2013.

Note

The term was coined by Thomas Touhey, as an evolution of CAS50 and CAS100 for the Classpad 300.

This protocol can be found over Serial transport and Serial transport over USB bulk. For serial links, the beginning of the communication always uses the same serial settings are always the same:

• Speed: 38400 bauds.

• Parity: none.

• Stop bits: 2.

Todo

This configuration may vary following command 0003 “Update link settings”. It is unknown as to how for now.

See the following sections for more details regarding the protocol.

• CAS300 packet format
  • 0x00 – Serial status packet
  • 0x01 – Command packet
  • 0x02 – Data packet
  • 0x06 – Acknowledge packet
  • 0x13 – Established packet
  • 0x15 – Out-of-order packet
  • 0x18 – Terminate packet
• CAS300 commands
  • 0000 “Start data transfer”
  • 0001 “End data transfer”
  • 0002 “Send device information”
  • 0003 “Update link settings”
  • 000C “Send file”
  • 000D “Request file”
  • 000E “Request file list”
  • 000F “Transfer file list”
  • 0010 ?
  • 0011 “Request device information”
• CAS300 flows