TODO_slave.md

Ideas for a CanOpen slave library

• Where? Fits best in master library (rename to node e.g.), because it shares many things like dictionary and eds_reader, and master could inherit from the slave class (-> inlining).

• Core::received_message:

  • implement two missing cases in receive loop (simple delegation to sdo/pdo class)

• PDO class:

  • Not much to do here. Just provide callbacks for RPDOs. These will be registered by Slave class.
  • Rename process_incoming_message() to process_incoming_tpdo() and add process_incoming_rpdo()
  • Rename add_pdo_received_callback() to add_tpdo_received_callback() and add add_rpdo_received_callback()

• SDO class:

  • Just like in PDO class, we need to implement client SDOs.
  • Slave class listens for requests and (add_request_callback()) and can react using send_response()
  • add add_client_sdo_callback(SDOReceivedCallback) (callback signature void(const SDOResponse&)) and/or add_request_callback(node_id, SDORequestCallback) (listening only for SDOs with slave's own node_id, callback signature void(index, subindex))
  • add send_response(node_id, index, subindex, vector<uint8_t> data) (chooses segmented/expedited transfer on it's own)
  • add abort_transfer(node_id, index, subindex, errorcode)

• Slave class:

  • has a node_id! (never used this until now...)
  • m_dictionary of type map<name, Entry>
  • m_index_to_name of type map<index,subindex,name>
  • add_entry(Entry)
  • read_dictionary_from_eds(filename) -> store default values
  • set_value(name,value) -> user should call this for all entries without default value
  • get_value(name) (internal use)
  • register sdo_request_callback -> get name from index, do get_value() and send result using core.sdo.send_response(node_id, index, subindex, value.get_bytes())
  • add_pdo_mapping(cob_id, name) -> core.pdo.add_rpdo_received_callback() with this cob_id -> set_value()...

• Master class:

  • inherit from slave
  • add at least mandatory entries using add_entry() in constructor

• EDSReader class:

  • handle default values but only if used by Slave class, otherwise dictionary could contain outdated values.