Abstract: The PLC according to the present disclosure includes a control module configured to perform a control operation according to a preset program; a first communication module configured to transmit a control command from the control module to at least one of first external devices; and a second communication module configured to transmit the control command from the control module to at least one of second external devices, wherein the first and second communication modules transmit external data to the control module via a data transmission cable which is shared with each other, and check interrupt signals therebetween to alternately transmit the external data to the control module, respectively.

Abstract: The PLC according to the present disclosure includes a control module configured to perform a control operation according to a preset program; a first communication module configured to transmit a control command from the control module to at least one of first external devices; and a second communication module configured to transmit the control command from the control module to at least one of second external devices, wherein the first and second communication modules transmit external data to the control module via a data transmission cable which is shared with each other, and check interrupt signals therebetween to alternately transmit the external data to the control module, respectively.

Abstract: Disclosed is a message processing unit provided in a PLC system including a master and a plurality of slaves. The message processing unit is provided to each of the slaves and includes a first filter configured to receive a message transmitted from the master and to determine whether the message is a broadcast message, a second filter configured to receive the message delivered from the first filter and to determine whether the message is a message-to-be-processed, and a processor configured to process the message he delivered from the first filter or the second filter.

Abstract: Embodiments provide a device and method for processing messages according to a priority order and for reducing a message processing time when a response event occurs, in a PLC communication module.

Abstract: A method for initializing expended modules in PLC (Programmable Logic Controller) system is provided in which an initialization request signal is generated and transmitted to a plurality of expended modules, when one basic unit initializes a plurality of expended modules, and an initialization completion signal is sequentially transmitted by the plurality of expended modules, when the initialization is completed, whereby the initialization time can be optimized, the method including performing an initialization operation after generating, by a basic unit, an initialization request signal and transmitting the initialization request signal to a plurality of expended modules, and determining that the initialization operation is completed, when an initialization completion signal is received from the expended modules connected to the basic unit.

Abstract: Disclosed is a message processing unit provided in a PLC system including a master and a plurality of slaves. The message processing unit is provided to each of the slaves and includes a first filter configured to receive a message transmitted from the master and to determine whether the message is a broadcast message, a second filter configured to receive the message delivered from the first filter and to determine whether the message is a message-to-be-processed, and a processor configured to process the message he delivered from the first filter or the second filter.

Abstract: Embodiments provide a device and method for processing messages according to a priority order and for reducing a message processing time when a response event occurs, in a PLC communication module.

Abstract: A method for initializing expended modules in PLC (Programmable Logic Controller) system is provided in which an initialization request signal is generated and transmitted to a plurality of expended modules, when one basic unit initializes a plurality of expended modules, and an initialization completion signal is sequentially transmitted by the plurality of expended modules, when the initialization is completed, whereby the initialization time can be optimized, the method including performing an initialization operation after generating, by a basic unit, an initialization request signal and transmitting the initialization request signal to a plurality of expended modules, and determining that the initialization operation is completed, when an initialization completion signal is received from the expended modules connected to the basic unit.