Control device, and control method for link activating and deactivating

A control device constituting at least a part of a control system, the control device comprising:

• a master control unit;
• and
• at least one slave control unit connected to the master control unit via a communication line, wherein
• the communication line comprises a first internal bus having a first uplink and a first downlink, wherein:
• the first downlink carries data from the master control unit to the at least one slave control unit;
• and
• the first uplink carries data from the at least one slave control unit to the master control unit,
• the master control unit comprises:
• a master transmission circuit coupled to the first downlink;
• a master reception circuit coupled to the first uplink;
• and
• a first processor configured with a first program to perform operations comprising:
• upon completion of a data transmission from the at least one slave control unit via the first uplink, transmitting a first instruction using the master transmission circuit, the first instruction for deactivating the first uplink to the at least one slave control unit via the first downlink and blocking a power source for supplying power to the master reception circuit;
• and
• in order to obtain data from the at least one slave control unit, transmitting a second instruction for activating the first uplink to the at least one slave control unit via the first downlink in which power is supplied from the power source to the master reception circuit, and
• the at least one slave control unit comprises
• a slave reception circuit coupled to the first downlink;
• a slave transmission circuit coupled to the first uplink;
• and
• a second processor configured with a second program to perform operations comprising:
• keeping the first downlink active by supplying power to the slave reception circuit,
• deactivating the first uplink by blocking a power source for supplying power to the slave transmission circuit, based on receiving, via the first downlink using the slave reception circuit, the first instruction from the master control unit transmitted via the first downlink, and
• activating the first uplink in which power is supplied to the slave transmission circuit, based on receiving, via the first downlink using the slave reception circuit, the second instruction from the master control unit transmitted via the first downlink.