Multiple mode communication interface for expansion device and PLC host and method for operating the same

A method for multiple mode communication interfacing for expansion device and PLC host, comprising steps of:

• setting expansion type, capacity and code for expansion device through a hardware mode setting connection module of a communication interface;
• forming a serial connection between a host and expansion devices by connecting the host and the previous-stage expansion device and next--stage expansion device through a previous-stage connection module and a next-stage connection module in the communication interface;
• setting I/O expansion number and pins through a first setting connection module and a second setting connection module;
• the host performing initialization step to judge the expansion type and capacity of the expansion device connected to the host and a normal connection with the expansion device by reading a signal from a judgment module;
• the host and an adjacent expansion device converting a code for sending to the expansion device;
• the expansion device automatically allowing or blocking the data sent from the host.

A method for multiple mode communication interfacing for expansion device and PLC host, comprising steps of:

• setting expansion type, capacity and code for expansion device through a hardware mode setting connection module of a communication interface;
• forming a serial connection with address line, data line and addressing line between a host and expansion devices by connecting the host and the previous-stage expansion device and next-stage expansion device through a previous-stage connection module and a next-stage connection module in the communication interface;
• forming a host mode output setting by connecting a first setting connection module and a second setting connection module of the communication interface to an output end of a memory unit;
• the host performing initialization step to judge the expansion type and capacity of the expansion device connected to the host and a normal connection with the expansion device by reading a signal from a judgment module;
• the host and an adjacent expansion device converting a code for sending to the expansion device;
• the expansion device automatically allowing or blocking the data sent from the host;
• the expansion device judging data accessing with the memory unit with reference to code and forming register path mode for bi-directional data exchange;
• and
• the host accessing temporary data in the memory unit through serial communication interface, and the expansion device accessing temporary data in the memory unit through host mode.

A method for multiple mode communication interfacing for expansion device and PLC host, comprising steps of:

• setting expansion type, capacity and code for expansion device through a hardware mode setting connection module of a communication interface;
• forming a serial connection with address line, data line and addressing line between a host and expansion devices by connecting the host and the previous-stage expansion device and next-stage expansion device through a previous-stage connection module and a next-stage connection module in the communication interface;
• forming a host mode output setting and a slave mode output setting by connecting a first setting connection module and a second setting connection module of the communication interface to two output ends of a memory unit;
• the expansion device performing a chip addressing step in power on;
• the host performing initialization step to judge the expansion type and capacity of the expansion device connected to the host and a normal connection with the expansion device by reading a signal from a judgment module;
• the host and an adjacent expansion device converting a code for sending to the device;
• the expansion device automatically allowing or blocking the data sent from the host;
• the expansion device judging data accessing with the memory unit with reference to code and forming register path mode for bi-directional data exchange;
• and
• the host accessing temporary data in the memory unit through serial communication interface, and the expansion device accessing temporary data in the memory unit through host mode.