Forney Engineering Company

Forney International, Inc.

Texas Instruments Corporation

Billy R Slater

Dennis W Simpson

Candelario Paredes

Alferd Gene Hufstedler

James S Grisham

Ronald Ray Weaver

Eric L Poe

Clarence T Carroll

In a sequence-of-events system for a distributed process control system, unfiltered changes in process element status are initially stored at each remote site along with a time tag. Each remote site has an I/O manager board to which are connected a number of individual I/O boards. Each I/O board in turn has connected to it process signal inputs from a number of process elements (e.g., 16), which can be in an 'on' or 'off' state. Each I/O board includes a change-of-state detector to which the process signal inputs are coupled. The change-of-state detector detects a change of state of any process input and generates an interrupt signal, which is coupled to a microprocessor also located on the I/O board. The microprocessor reads the status of all the process element inputs coupled to the scanner and also the output of a local clock on the I/O board. The microprocessor records in a sequence-of-events memory on the I/O manager board the status of all process signal inputs to the change-of-state detector at the time of a change in any input, along with the relative time at which the change occurred.

Sequence of events system using a redundant analog I/O board system

In a triac power switching system, two triacs are connected in series between an AC power source and a load. Each time power is applied to a load, the triacs are tested by first turning on one of the triacs while maintaining the other triac turned off, then turning on both triacs to apply power to the load for a set time interval and then turning off one of the triacs and determining whether power is still applied to the load. If power is applied to the load while either one of the triacs is supposed to be off, an alarm is sounded. In addition, if power is not applied to the load when both triacs are turned on, an alarm is sounded.

Triac power switching and testing system

A combined mode program-panel controller method for a distributed industrial process control system permits a system operator to configure the overall system architecture to control the sequential operation of the entire system or a sub-portion thereof. The program-panel controller includes a first user accessible graphic program by which the system architecture can be symbolically reconfigured and a second user accessible instruction set program by which the operating parameters of the so-configured system or a sub-portion thereof may be altered.

Combined mode supervisory program-panel controller method and apparatus

An industrial process control system in accordance with the present invention includes a plurality of device controllers connected together through a common buss with each device controller connected to an associated controlled device(s) that effect process control. A computer-aided system interface for controlling the overall system includes a visual display device in the form of a multi-color CRT and a graphic input device in the form of a transparent touch-responsive panel that overlies the CRT display screen. Computer generated symbols representing the controlled devices are displayed on the CRT screen to define touch-responsive target areas. When an appropriate target area is touched by a human operator, a signal, such as a command signal, is generated to cause the controlled device whose symbol is displayed in the designated target area to respond, with this response being then indicated by a change in the device symbol being displayed on the screen. Other features include generation of a 'hit' display to indicate the last coordinates on the display screen touched by the operator, a two-step execute command sequence for entering high priority commands into the system, and the changing of analog set point values as a function of the time that a selected target area is touched. The system advantageously eliminates some, if not all, input through a conventional keyboard so that the system operator interfaces with the system through easily comprehended and non-ambiguous visual symbols.

Industrial process control system

A control system for controlling an industrial process includes a plurality of remotely located process control units (remotes) each coupled to an associated input/output device(s) and adapted to communicate with one another through a dual channel communications link. Each remote has a unique succession number within a predetermined succession order with supervisory communication-control of the communication link sequentially transferred to each remote according to its succession number to provide a revolving or master for the moment control of the system. Digital information in the form of data and control information blocks is transmitted between the remotes with the blocks transmitted twice on each channel of the communications link. The destination remote tests the block validity on one of the two dual channels and, if validated, responds with an acknowledgement signal (ACK) and, if invalid, tests the blocks on the other, alternate channel and then responds with an acknowledgement or non-acknowledgement signal (NAK) depending upon whether the data blocks tests on the alternate channel are found valid or invalid. A non-acknowledgement from the destination remote re-triggers the transmission of the blocks from the source remote. The system provides high overall operating efficiency since the remotes will maintain a system-like integrity on each side of a severed communication link and the redundant block transmission with alternate line checking provides very high information transfer reliability.

Industrial control system

In an industrial control system, a plurality of remote data processing units communicate with one another over a communications link. Some of the processing units called primary remotes have inputs and outputs and control a process operation in response to signals received on the inputs by signals transmitted over the outputs. One or more of the remote processing units, referred to as a redundant remote, monitors a plurality of the other primary remotes to determine whether any of the monitored primary remotes has failed. If any of the primary remotes fails, the redundant remote takes over operation of the process controlled by the failed primary remote by sending instructions and commands over the communications link interconnecting the primary and redundant remotes.

An improved controller for vibratory seismic energy sources insures that the energy imparted to the ground by the source is in phase with the reference signal. Phase lock is achieved in a manner which minimizes the effects of the attendant frequency distortion. On upsweeps when the phase error is greater than some threshold level, phase lock is achieved by slowing down the drive signal, thereby introducing frequency distortion which falls below the bandpass of the sweep signal. On downsweeps when the phase error is above some selected threshold, phase lock is achieved by speeding up the drive signal, thereby resulting in frequency distortion which falls above the bandpass of the sweep signal.

Method and system for achieving vibrator phase lock

There has been provided an improved process control optimizer for regulating at least one parameter of the process relative to optimum utilization of available energy. Temperature responsive open loop control means regulates the fuel flow and the optimizer is operatively responsive to the fuel flow for regulating air flow for combustion of fuels such that the fuel air mixture is minimized. The improvement includes a means for delivering a digital output code for governing the air mixture in accordance with the optimum characteristic of the process and digitally responsive means receive said codes for decreasing air at a selected first rate and increasing air at a relatively faster second rate, the rates corresponding to respective reductions and increases in fuel flow about a selected optimum operating point.

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Plano, TX, United States of America

Billy R Slater