Master Synchronisation

A method of enabling synchronisation of a second clock at a second device with a first clock of a first device, the method comprising, at said first device:

• transmitting a first message comprising an identifier to the second device;
• generating a timestamp in dependence on the time at which the first message is transmitted from the first device according to the first clock;
• generating a second message comprising the identifier and the generated timestamp;
• and
• transmitting the second message to the second device.

A system comprising a first master device and a first slave device, wherein the first master device comprises:

• a first clock;
• a first communications interface configured to transmit a first message comprising an identifier to the first slave device and generate a first timestamp in dependence on the time at which the first message is transmitted from the first master device according to the first clock;
• and
• a first controller configured to generate a second message comprising the identifier and the generated first timestamp, wherein the communications interface is further configured to transmit the second message to the first slave device,
• wherein the first slave device comprises:
• a second clock;
• a second communication interface configured to:
• receive the first message comprising the identifier from the first master device and generate a second timestamp in dependence on the time at which the first message is received at the first slave device according to the second clock;
• and
• receive the second message from the first master device;
• and
• a second controller configured to adjust the second clock in dependence on a time difference between a time indicated by the first timestamp and a time indicated by the second timestamp.