Real time process controller with serial I/O bus

A process control system for monitoring and controlling elements of a physical process in real time, said system comprising:

• an electrical conductor;
• a plurality of local control modules electrically connected to each other in series configuration through the electrical conductor;
• a control unit electrically connected through the electrical conductor to the series configuration of the local control modules;
• means for electrically connecting the local control modules to selected elements of the process;
• means in each local control module for determining operating status of process elements to which the module is electrically connected;
• means in each local control module and responsive to said determining means for identifying selected status conditions;
• means responsive to the identifying means for accessing the control unit to enable communication of the identified selected status conditions directly from a local control module to said control unit, with said communication of the selected status conditions having priority over other types of communications between the control unit and other local control modules;
• and
• means in the control unit and responsive to receipt of said selected status conditions for transmitting signals to a selected local control module in priority over all other actions of the control unit in order to control a function of a process element to which the selected local control module is connected, and thereby effect a desired change in said function of said process element.

A process control system for monitoring and controlling elements of a physical process in real time, said system comprising:

• a central control unit;
• a serial data bus electrically connected to the central control unit and having a plurality of electrical conductors extending within said bu;
• a plurality of control modules;
• means for removably securing said control modules in electrical contact with at least one of said electrical conductors so that said control modules are electrically connected to said control unit;
• means for removably securing said control modules in electrical contact with selected elements of the process;
• means in said modules for monitoring operating status of process elements to which the modules are electrically connected;
• means in said modules responsive to the monitoring means for identifying selected status conditions of the monitored process elements;
• means in said modules responsive to the identifying means for obtaining priority communications access to the control unit;
• means for communicating said selected status conditions from a control module directly to the control unit by means of said priority communications access;
• and
• means in said control unit and responsive to said selected status conditions for transmitting signals to a selected control module in priority over all other communications between the control unit and any control module, in order to control operation of a process element electrically connected to the selected control module, thereby effecting a desired change in said function of said process element.

A process control system for monitoring and controlling elements o a physical process in real time, the system comprising:

• a central control unit;
• a serial data bus electrically connected to the central control unit and having a plurality of electrical conductors extending within said bus;
• and
• a plurality of control modules which are each removably secured in electrical connection with electrical conductors in said serial data bus in a series configuration, and which are each removably secured to an element of the process, wherein first selected ones of said control modules each monitor at least one process element and communicate, on a priority basis directly to the control unit, data identifying existence of selected status conditions of said at least one process element, and wherein second selected ones of said control modules each control operation of at least one selected process element in response to command signals from the control unit and receive, on a priority basis, control signals transmitted directly from the control unit in response to said data identifying selected status conditions, which signals effect desired changes in operation of said at least one selected process element.

A process control system for monitoring and controlling elements of a physical process in real time, the system comprising:

• a central control unit;
• at least one remote module electrically connected to the central control unit and to an element of the process for communicating information relating to operation of the element of the process on a priority basis and independent of operator intervention directly to and from the central control unit;
• and
• a video device electrically connected to the control unit for visually presenting information received from said remote module, said video device responsive to user input for producing signals causing communication of control instructions from the control unit to the remote module, and said video device responsive to user input to present selected information visually in a format and configuration specified by the user.

In a process control system having a plurality of control modules electrically connected in a series configuration to a control unit, and with said control modules electrically connected to elements of a physical process to be controlled in real time, a method of controlling the process comprising the steps of:

• addressing selected control modules from the control unit by providing a serial sequence of signals to each of said control modules, wherein the sequence of signals identifies a selected control module;
• providing an electrical signal in the selected control module indicating status of a monitored process element;
• in response to the sequence of signals, communicating said status to the control unit;
• in the control modules, detecting selected status conditions of the monitored element;
• in response to detection of selected status conditions, communicating a signal identifying said selected status conditions directly from a plurality control module which detected said selected status conditions to the control unit independent of said sequence of signals;
• and
• in response to receipt of the selected status conditions, communicating a signal directly from the control unit to a selected control module on a priority basis over other signals, in order to control a function of the monitored process element and to thereby effect a desired change in the function of the process element.