Supervisory control system

Claim 2

A process control station for effecting a control function in a process-controlling device by supplying a true-value analog control signal over an output line, a device supplying a condition-indicating signal, the improvement including in combination, a first control link connected to said output line and receiving said true-value analog control signal for supplying the analog control signal, a second control link having an electronic analog memoryamplifying means and an analog controller with an input signal means and an output signal means, said second control link receiving at least one of said signals and being responsive to said received signal to adjust said controller to be capable of independently supplying a backup analog control signal substantially identical to said analog control signal supplied by said first link, said input signal means consists of first and second input portions and said analog controller output signal means being connected to first input portion for supplying said backup analog control signal thereto and said output line being connected to said second input portion for supplying said analog control signal thereto, and, said condition-indicating signal being supplied to said electronic analog memory amplifying means and said electronic analog-memory amplifying means supplying a signal to said input signal means to adjust said analog controller to the condition of a process being controlled.

Claim 3

The process control station of claim 1 wherein said first control link has an electrically alterable analog memory with amplifier means for supplying said analog control signals.

Claim 4

The process control station of claim 2 further including output line-switching means for selectively connecting said output line to said first control link for receiving said analog control signal or to said second control link analog controller for receiving said backup control signal.

Claim 5

A process control station as set forth in claim 3 wherein said output line-switching means includes condition-responsive means operatively associated with said first control link and responsive to a predetermined condition in said first control link to actuate said output line-switching means to switch to said second control link.

Claim 6

The process control station of claim 1 wherein said first control link includes an electrically alterable electronic-type analog memory amplifier for storing and supplying said analog control signal and having an input gating portion for receiving analog input signal to alter the stored signal, a third control link having a manual controller supplying a predetermined analog control signal, switching means electrically interposed between said output line of all of said control links for selectively connecting any one of said control links to said output line, and further switching means in said second control link selectively interconnecting said analog controller input signal means to said electronic analog-memory amplifying means and for disconnecting said output line from said electronic analog-memory amplifying means.

Claim 7

THe process control station of claim 1 wherein said first control link has an electrically alterable electronic-type analog memory amplifier for supplying said analog control signal and further including input gating means for receiving an analog input signal to be stored, digital control element means including station-selection means and digital analog converter means, said converter means and said station-selection means being connected to said input gating means for selectively supplying an analog input signal to said analog memory amplifier of said first control link and said process-controlling device supplying said condition-indicating signal to said digital control element.

Claim 8

A process control system having a central station for monitoring and effecting a control over a plurality of remote stations, each of said remote stations having a process-controlling device responsive to an analog control signal for effecting a function and supplying a condition-indicating signal indicative of the function being effected, the improvement including in combination, a digital control element in said central station operative to supply digital control signals, a digital-to-analog signal converter means in said central station responsive to said digital control signals to supply an analog input signal indicative of said digital control signals, said converter supplying said analog signals to all of said remote stations, means in the digital control element receiving said condition-indicating signals from all of said remote stations, station-selection array means in said central station for supplying selection signals to said remote stations with each remote station being responsive to a unique set of station-selection signals to accept said analog input signal only when indicated by said station-selection signals, each station including a plurality of independent control links selectively connectable to an output control line for furnishing an analog control signal to a process-controlling device, a first one of said control links being jointly responsive to an analog signal supplied by said converter and to its unique set of station-selection signals to store said analog input signal and supply an analog control signal substantially identical to said stored analog input signal, a second control link selectively jointly responsive to said analog input signal and to said station-selection signals unique to the respective station for receiving and storing said analog input signal and selectively operative to supply an analog control signal to said output line, switching means electrically interposed between said first and second ones of said control links for selecting the analog control signal, means in said second one of said control links for receiving and storing said condition-indicating signal and operative to supply a signal indicative of the condition of the process being controlled as an analog control signal.

Claim 9

A process control system having a central station for monitoring and effecting a control over a plurality of remote stations, each of said remote stations having a process-controlling device responsive to an analog control signal for effecting a function and supplying a condition-indicating signal indicative of the function being effected, the improvement including in combination, a digital control element in said central station operative to supply digital control signals, a digital-to-analog signal converter means in said central station responsive to said digital control signals to supply an analog input signal indicative of said digital control signals, said converter supplying said analog signals to all of said remote stations, means in the digital control element receiving said condition-indicating signals from all of said remote stations, station-selection array means in said central station for supplying selection signals to said remote stations with each remote station being responsive to a unique set of station-selection signals to accept said analog input signal only when indicated by said station-selection signals, each station including a plurality of independent control links selectively connectable to an output control line for furnishing an analog control signal to a process-controlling device, a first one of said control links being jointly responsive to an analog signal supplied by said converter and to its unique set of station-selection signals to store said analog input signal and supply an analog control signal substantially identical to said stored analog input signal, a second control link selectively jointly responsive to said analog input signal and to said station-selection signals unique to the respective station for receiving and storing said analog input signal and selectively operative to supply an analog control signal to said output line, switching means electrically interposed between said first and second ones of said control links for selecting the analog control signal, means in said second one of said control links for receiving and storing said condition-indicating signal and operative to supply a signal indicative of the condition of the process being controlled as an analog control signal.

Claim 10

The system of claim 7 wherein each remote station further includes a third control link having a manual controller and said switching means operative selectively connect any one of said control links to said output line.

Claim 11

The system of claim 7 wherein said first and second control links each have an electrically alterable electronic-type analog memory amplifier for storing and receiving said analog input signal and said second control link having an analog controller selectively receiving said condition-indicating signal as a set point input and said analog control signal of said second control link having variable input and when connected to said output line having switching means selectively connecting said set point input to said analog memory amplifier in said second control link and switching said condition-indicating signal to said variable input and each of said remote stations being operatively independent one on the other.

Claim 12

Subject matter of claim 9 further including condition-responsive means sensiNg a parameter operatively connected to said switching means for selecting one of said control links to supply analog control signal to the process-controlling device in accordance with the sensed parameter.