Optical measurement apparatus having a synchronizing function of synchronizing time between a master device and a slave device, and connectable to an industrial network

An optical measurement apparatus having a synchronizing function of synchronizing time between a master device and a slave device, and connectable to an industrial network, the optical measurement apparatus comprising:

• an interface unit configured to receive a synchronization signal transmitted from the master device to the industrial network at a constant communication cycle, and output, in synchronization with the synchronization signal, a result of measurement by the optical measurement apparatus and a synchronization supervisory signal having a first state and a second state;
• and
• a measuring unit configured to execute at least one optical measurement process at a measurement cycle different from the communication cycle and generate the measurement result and the synchronization supervisory signal,
• wherein
• the measuring unit is configured to switch the synchronization supervisory signal from the second state to the first state in synchronization with receipt of the synchronization signal by the interface unit after start of the measurement, and is configured to switch the synchronization supervisory signal from the first state to the second state in synchronization with receipt of the synchronization signal by the interface unit when the interface unit outputs the measurement result.