Abstract: A method and apparatus for providing an active standby control system includes the steps of providing a first and second programmable logic controller (PLC), each controller having an operating state. Each controller includes a network module board operably connected to a network; a control unit, a remote I/O head; and, a hot standby module, each hot standby module is operably connected together. PLC. This method and apparatus can be used within a control system for monitoring input devices and for controlling output devices which reside on the standard communications network such as an Ethernet network, and the standard communications protocol used therein can be TCP using Modbus.

Abstract: A method, system, and computer program product for communicating information over a communications network from a sending device to a target device is disclosed. The sending device determines a network location of a target device to which a first frame of information is to be sent. The first frame of information is formatted for a first communications protocol and includes a device address field configured to store a device identifier that corresponds to the target device. Then the sending device selects, based on the network location of the target device, an addressing scheme from among plural different addressing schemes. The device identifier is generated for the first frame on the basis of the selected addressing scheme. The sending device encapsulates the first frame of information in a second frame of information formatted for a second communications protocol and including a destination address field.

Abstract: A method and apparatus for providing an active standby control system comprising the steps of providing a first and second programmable logic controller (PLC), each controller having an operating state. Each controller further including a network module board operably connected to a network; a control unit, a remote I/O head; and, a hot standby module, each hot standby module is operably connected together. Operably connecting each programmable logic controller to a network. Assigning a network address identifier, i.e., Internet Protocol or Media Access Control address, to each programmable logic controller and sensing the operating state of each programmable logic controller. The network address identifier of each programmable logic controller is determined by the operating state of each respective programmable logic controller.

Abstract: A method, system, and computer program product for communicating information over a communications network from a sending device to a target device is disclosed. The sending device determines a network location of a target device to which a first frame of information is to be sent. The first frame of information is formatted for a first communications protocol and includes a device address field configured to store a device identifier that corresponds to the target device. Then the sending device selects, based on the network location of the target device, an addressing scheme from among plural different addressing schemes. The device identifier is generated for the first frame on the basis of the selected addressing scheme. The sending device encapsulates the first frame of information in a second frame of information formatted for a second communications protocol and including a destination address field.

Abstract: The present invention is directed to an apparatus for communication with at least one device which resides on a standard communications network using a standard communications protocol. The apparatus has a scanner for scanning the device, a device scan table for storing data relating to the device, and a standard communications interface for interfacing between the device scanner and the standard communications network using the standard communication protocol. The present invention is also directed to a device scanner for a first device located on a first node of a standard communications network. The device scanner is provided for scanning devices on the standard communications network, and for identifying a second device on a second node of the standard communications network.