Steeplechase Software, Inc.

Allen-bradley Company, LLC

Motorola Corporation

Michael T Klein

Richard Leroy Mahn

William Perry Su

Per-Ola Gustav Forsgren

Mark A Lucak

Jonathan R Engdahl

Donald J Voss

Don C Stokes

Jonathon R Engdahl

A digital computer implemented software system is provided that translates a graphical flow chart into a control program and displays the same upon a visual display attached to the digital computer during execution of a control program. The graphic flow chart includes a diagnostic decision block for automatically generating a diagnostic program based on user-entered error condition parameters. The diagnostic decision block replaces manual programming of each parameter and each block in the diagnostic program, reducing maintenance time when the parameters need to be updated. Specific problem solving steps can also be programmed as parameters to aid a machine operator in locating and fixing errors in the manufacturing process.

Diagnostic software for facilitating flowchart programming

A digital computer implemented software system is provided which translates a control program into a graphical flow chart and displays the same upon a visual display attached to the digital computer during execution of a control program. The graphical flow chart includes multiple flow paths of execution, each flow path having a respectively associated binary memory location. Each memory location has an initial value of zero, and the value of a particular memory location increases to one upon execution of the control program along the flow path associated with that particular memory location. When a memory location has a value of one, the flow path associated therewith is visually enhanced upon the visually displayed graphical flow chart. A user is provided with a function to reset each memory location value to zero at any time during execution of the control program.

Animation of execution history

A digital computer implemented software system is provided for enabling on-line programming changes of industrial logic controllers using a software package of the type utilizing graphical flowcharts is provided, allowing a user to modify a program and transfer industrial process state information while the program is controlling equipment. A control program has predetermined stop points of execution. Each stop point is assigned a unique index used to retrieve instruction addresses from an array. Each stop point also is associated with industrial process state information. By substituting new addresses pointing to stop points in a new program for the executing program addresses and transferring the state information, the executing program is replaced by a new program when execution continues on the next CPU scan. On-line programming changes take effect by replacing the executing code when all programs have reached a stop point, and by restarting a second program from the corresponding stop point in the second program.

Online programming changes for industrial logic controllers

A digital computer implemented software system is provided for programming industrial logic controllers using a software package of the type utilizing relay ladder logic to represent control programs. The control program is executable by the controller to control the operation of one or more industrial devices. Using relay ladder logic, the control programmer is provided with a system to replace a coil with an ACTION block containing at least one complex expression. When the left side of the ACTION block is energized, the expression is evaluated. In a further embodiment, the programmer is able to replace a contact with a DECISION block containing a Boolean expression. When the left side of the DECISION block is energized, the Boolean expression is evaluated. If the expression evaluates as TRUE, the right side of the DECISION is energized.

Extended relay ladder logic for programmable logic controllers

An interface circuit couples a host processor in an industrial control system to a local area communications network. In includes a protocol machine for receiving and transmitting messages on the network and an interface controller which is programmed to implement one or more protocols. As a message is received by the protocol machine, the interface controller anticipates a responsive message which it writes to the protocol machine even as the message is being received. If the message is received accurately, the responsive message is transmitted without delay.

Intelligent network interface circuit

A demodulator for a phase coherent frequency shift keyed signal has a master clock which generates a signal having a plurality of pulses during each half of the bit internal of the FSK signal. A detector determines during which master clock pulse within several groups of X number of pulses the most transitions occur in the received signal. Based on the determined clock pulse, samples taken in each of two consecutive half-bit intervals of the FSK signal are selected for comparison to produce the demodulator output signal.

Digital FSK signal demodulator

A circuit and method for demodulation of transmitted phase-coherent signals including recovery of the clock and data signals associated therewith. A clock recovery circuit detects a zero crossing of the transmitted signal which occurs every one-half period of the lowest frequency transmitted signal. A data recovery circuit detects the presence or absence of a zero crossing during a window portion of each one-half period of the lowest frequency transmitted signal.

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Ann Arbor, MI, United States of America

Michael T Klein