Abstract: The present invention relates to a system and methodology facilitating network communications between an industrial control system and a client application that interacts with a plurality of data items on the control system. The client application initiates a request or query to the industrial control system for an identification of selected data items of interest. Based on information received in the request, an aggregation component can be constructed by the client, wherein names and buffer allocations relating to the data items of interest are provided. The aggregation component is then installed by the client and updated in the industrial control system, thus providing information access to the client application when fresh or updated information is desired. Information is accessed via a communications packet that is generated from the data items identified in the aggregation component.

Abstract: The present invention relates to a system and methodology facilitating network communications between an industrial control system and a client application that interacts with a plurality of data items on the control system. The client application initiates a request or query to the industrial control system for an identification of selected data items of interest. Based on information received in the request, an aggregation component can be constructed by the client, wherein names and buffer allocations relating to the data items of interest are provided. The aggregation component is then installed by the client and updated in the industrial control system, thus providing information access to the client application when fresh or updated information is desired. Information is accessed via a communications packet that is generated from the data items identified in the aggregation component.

Abstract: A programmable controller senses the status of input devices and controls the state of operating devices in accordance with a stored ladder logic control program. A memory of the programmable controller contains message data and data defining a set of expected transitions of the status of selected input devices. An instruction of the ladder logic initiates execution of a machine language message program which causes the programmable control to inspect the states of the selected input devices to determine whether an expected transition has taken place. When one of the expected transitions occurs, the message data and an identification of the selected input device are sent to a personal computer connected to the programmable controller. The personal computer uses the the data from the programmable controller to formulate an alphanumeric message which is presented to the operator on a display device.

Abstract: A programmable controller for sensing the status of input devices and controlling the state of operating devices in accordance with a stored ladder logic control program includes a state machine instruction. A memory is provided for storing data regarding each state of an apparatus being controlled. This data defines the status of apparatus operating devices for each state, and the legitimate transitions from that state to other selected states, along with a Boolean logic expression of selected input conditions which determines when a state transition should occur. A processor responds to the state machine instruction by examining the truth of the Boolean logic expressions for the present state of the apparatus to detect if a state transition should occur. Upon such a detection controller advances to the state associated with the detected true expression. State transitions also can be defined as occurring upon a specified change in the status of a single input.

Abstract: High-level language motion control programs are downloaded and uploaded between a programming terminal and a remotely located I/O module through a peer-to-peer network and a programmable controller system processor. Automatic block transfer between the programmable controller system processor and the I/O module is executed in response to commands from the programming terminal. The programmable controller processor and motion control I/O module are modified to handle two types of block transfers, the first controlled from the user applications program of the programmable controller processor, and the second controlled from the programming terminal.

Abstract: A programmable controller for sensing the status of input devices and controlling the state of operating devices in accordance with a stored ladder logic control program includes a step sequencer. A memory is provided for storing data regarding each step of the sequence. This data defines the operating device states for each step, and the legitimate transitions from that step to other selected steps in the sequence, along with the input status conditions which trigger a step transition. A processor responds to a ladder logic instruction by comparing the status of the input devices to the stored input status conditions for the current step to detect if a step transition should occur. Upon such a detection the sequencer advances to the step associated with the detected input status condition. Should an illegal transition from one step to another occur, an error message is generated.

Abstract: A program in a higher-level language for a programmable controller is stored as a hex-coded file in a memory in a main processor unit. The file is downloaded to a processor-based I/O logic module that translates the program into a multi-table data structure for relating the state of output devices on controlled equipment to the state of input devices on the equipment. After translation, an I/O control routine of lower-level, machine-language processor instructions is executed every 500 microseconds to control the output devices in response to changing conditions at the input devices and in response to the output functions embedded in the data structure as a result of translating the downloaded program. In a first embodiment the higher-level language is of the ladder-diagram type, while in a second embodiment the higher-level language incorporates state transition logic.