Environmental control system

An environmental control system comprising:

• a plurality of communication interface means for providing bidirectional data communication over an alternating current power transmission line, each communication interface means being coupled to the power transmission line;
• a central processing unit coupled to a first communication interface means, said central processing unit performing data manipulation and processing responsive to stored instructions and received communications from said coupled communication interface means;
• means for changing an environmental temperature and humidity condition in a space;
• and
• peripheral control means for controlling said means for changing an environmental condition coupled to a second communication interface means, said peripheral control means being located remotely with respect to said central processing unit and being controlled by and communicating with said central processing unit via the communication interface means over the power transmission line at periodic time slots assigned to said peripheral control means by said central processing unit.

A system for controlling an environment such as in a greenhouse and for operating over an AC power transmission line, said system comprising:

• a plurality of communications means, each of selectively providing communications between other individual communications means over the AC power transmission line;
• a central control processor, coupled to one of said communications means, for performing data processing and manipulation responsive to stored data and received communications and for generating environmental commands responsive to stored data and received communications;
• peripheral control means, coupled to a second communications means and located remotely with respect to said central control processor, for selectively controlling remotely located peripheral equipment in response to said environmental commands;
• said one communications means and said second communications means communicating with one another at periodic time slots assigned to said peripheral control means by the central control processor;
• and
• peripheral equipment, coupled to the peripheral control means, for selectively performing an environmental control function in response to the peripheral control means.

A control system adapted to communicate over an AC power line between a plurality of remote peripheral elements and a central processing unit, said control system comprising:

• the peripheral elements including at least one sensor element for sensing and storing the value of an actual physical parameter;
• each sensor element communicating with a communication interface unit coupled to the power line;
• the peripheral elements further including at least one actuator element for controlling the position of an actuator device affecting a controlled parameter, each actuator element communicating with a communication interface unit coupled to the power line;
• said communication interface units providing bidirectional communication over the power line between the central processing unit and said at least one sensing element, and providing bidirectional communication over the power line between the central processing unit and said at least one actuator element, said bidirectional communication occurring at periodic time slots assigned to each peripheral element by inputs to the central processing unit;
• and
• the central processing unit further adapted to perform a control sequence including an interrogation of the peripheral elements by the processing unit wherein, in response to said interrogation during its time slot, said at least one sensor element replys with an answer indicative of the actual value of the physical parameter it is sensing;
• wherein, in response to receiving the value of the physical parameter, the central processing unit calculates a desired position of the actuator element which is based at least in part on the physical parameter;
• and wherein, in response to said interrogation during its time slot, said at least one actuator element replys with an acknowledgement and receives in turn said desired position to control the position of the actuator device;
• whereby the central processing unit controls said at least one actuator element and thereby said controlled parameter based upon, at least in part, input from said at least one sensing element.