Node for a communication bus system

A node for a ternary modulation communication bus system, the node comprising:

• a controller;
• a receiver configured to detect a ternary modulation state on the communication bus;
• and
• a signal driver configured to apply a ternary modulation state to a communication bus, wherein the ternary modulation state comprises one of:
• a first dominant state;
• a second dominant state;
• or
• a recessive state;
• wherein, during an enumeration process, the controller is configured to:
• receive an enumeration signal from the communication bus via the receiver;
• in response to the enumeration signal, control the signal driver to apply a sequence of ternary modulation states at a respective sequence of timeslots to the communication bus to represent a unique identifier of the node according to an enumeration encoding scheme,
• wherein the enumeration encoding scheme comprises one or more ternary encoding rules comprising:
• at each time slot the signal driver only applies the recessive state or a predetermined one of the first dominant state and the second dominant state specific to the time slot.

A method of enumerating a node on a ternary modulation communication bus system, the method comprising:

• receiving, at the node, an enumeration signal from a communication bus of the ternary modulation communication bus system;
• encoding a sequence of ternary modulation states representing a unique identifier of the node according to an enumeration encoding scheme, wherein each ternary modulation state comprises one of:
• a first dominant state;
• a second dominant state;
• or
• a recessive state;
• applying each ternary modulation state to the communication bus at a respective timeslot of a corresponding sequence of timeslots;
• determining the node to win an arbitration process if, for each timeslot of the sequence of timeslots, the ternary modulation state applied to the communication bus matches a persistent ternary modulation state that persists on the bus for the timeslot;
• and
• determining the node to lose an arbitration process if, for any timeslot of the sequence of timeslots, the ternary modulation state applied to the communication bus differs from the persistent ternary modulation state that persists on the bus for the timeslot;
• wherein the enumeration encoding scheme comprises one or more ternary encoding rules comprising:
• at each time slot the node only applies the recessive state or a predetermined one of the first dominant state and the second dominant state specific to the time slot.