Sequence counting encoder monitor

Claim 2

A sequential monitoring system comprising a control center including control means for generating shift pulses; a plurality of field encoders disposed at locations remote from said control center, each of said field encoders including a shift register stage and means responsive to energization of said shift register stage for generating signals in accordance with conditions to be monitored; and cable means interconnecting said control center and said field encoders, said cable means including a wire for supplying said shift pulses from said control center to each of said field encoders and wires for supplying said condition signals from said field encoders to said control center; said shift register stages of said field encoders being serially interconnected and each having shift input means connected with said wire for supplying said shift pulses whereby said shift register stages are sequentially energized to provide sequential scanning of said plurality of field encoders at said control center.

Claim 3

The invention as recited in claim 1 wherein said cable means includes wires common to each encoder to carry said shift pulses and said condition signals whereby any number field encoders may be added to the monitoring system without the necessity of additional wires connected with the said control center.

Claim 4

The invention as recited in claim 1 wherein each of said field encoders includes means for generating an acknowledge pulse when the shift register stage associated with each of said field encoders is energized, and said cable means includes a wire common to each field encoder for supplying said acknowledge pulses to said control center.

Claim 5

The invention as recited in claim 3 wherein said control center includes counting means for receiving and counting said acknowledge pulses such that the field encoder being monitored may be determined from said counting means.

Claim 6

The invention as recited in claim 4 wherein said control means includes shift pulse generating means operable in response to the receipt of an acknowledge pulse to generate a shift pulse.

Claim 7

The invention as recited in claim 5 wherein said control means includes gating means receiving said acknowledge pulses and responsive thereto to operate said shift pulse generating means, time delay means connected with said shift pulse generating means, internal acknowledge pulse generating means connected with said time delay means to generate an internal acknowledge pulse a predetermined time after a shift pulse is generated if no acknowledge pulse is received in the interim, and means supplying said internal acknowledge pulse to said gating means to operate said shift pulse generating means.

Claim 8

The invention as recited in claim 6 wherein said control center includes recording means connected with said internal acknowledge pulse generatiNg means and said counting means to record data indicating by count which field encoder failed to generate an acknowledge pulse.

Claim 9

The invention as recited in claim 7 wherein said counting means is connected with said gating means to count pulses corresponding to said acknowledge pulses and said internal acknowledge pulses.

Claim 10

The invention as recited in claim 6 wherein said control means includes control pulse generating means for generating a control pulse at the commencement of a scan, said shift register stage in each field encoder having control input means for receiving control pulses and output means, and said cable means includes wires connecting the output means of each shift register stage to the input means of the shift register stage in the next succeeding field encoder and connecting the control pulse generated at said control center to the input means of the shift register stage in the first field encoder.

Claim 11

The invention as recited in claim 9 wherein said control means includes override pulse generating means connected with said internal acknowledge pulse generating means to generate an override pulse in response to an internal acknowledge pulse, each of said field encoders includes bypass means connected from the input means to the output means of each shift register stage, and said cable means includes a wire common to each field encoder to supply said override pulse to the bypass means of each field encoder whereby a control pulse at the input means of the shift register stage of a field encoder that fails to generate an acknowledge pulse bypasses the shift register stage to the output means thereof such that a fault at one field encoder does not inhibit the continuous scanning operation of the monitoring system.

Claim 12

A sequential monitoring system comprising a control center including control means for generating shift pulses and scan initiation means connected with said control means and having an alarm input for receiving an alarm signal; a plurality of field encoders disposed at locations remote from said control center, each of said field encoders including a stage of a shift register for receiving said shift pulses and means for generating signals in accordance with conditions to be monitored, said signal generating means in each of said field encoders including alarm signal generating means for providing an alarm signal in response to an alarm condition existing at the field encoder; and cable means interconnecting said control center and said field encoders, said cable means including a wire for supplying said shift pulses from said control center to each of said field encoders, wires for supplying said condition signals from said field encoders to said control center and a wire common to each field encoder for supplying said alarm signal to said alarm input of said scan initiation means; said scan initiation means including scan initiation pulse generating means for supplying said control means with a scan initiation pulse in response to said alarm signal to cause the generation of said shift pulses by said control means whereby the monitoring system scans said field encoders to find the field encoder from which said alarm signal was generated.

Claim 13

A sequential monitoring system comprising a control center including control means for generating shift pulses and scan initiation means connected with said control means and having an alarm input for receiving an alarm signal; a plurality of field encoders disposed at locations remote from said control center, each of said field encoders including a stage of a shift register for receiving said shift pulses and means for generating signals in accordance with conditions to be monitored, said signal generating means in each of said field encoders including alarm signal generating means for providing an alarm signal in response to an alarm condition existing at the field encoder; and cable means interconnecting said control center and said field encoders, said cable means including a wire for supplying said shift pulses from said control center to each of said field encoders, wires for supplying said condition signals from said field encoders to said control center and a wire common to each field encoder for supplying said alarm signal to said alarm input of said scan initiation means; said scan initiation means including scan initiation pulse generating means for supplying said control means with a scan initiation pulse in response to said alarm signal to cause the generation of said shift pulses by said control means whereby the monitoring system scans said field encoders to find the field encoder from which said alarm signal was generated.

Claim 14

The invention as recited in claim 11 wherein each of said field encoders includes alarm identification means for providing a signal indicating that an alarm condition exists at the field encoder, and said cable means includes a wire common to each field encoder and connected with said control means whereby the field encoder at which an alarm condition exists may be identified during scanning of said field encoders.

Claim 15

The invention as recited in claim 12 wherein each of said field encoders includes clear identification means for providing a signal indicating that an alarm condition existing at the field encoder has been corrected, and said cable means includes a wire common to each field encoder and connected with said control means whereby the field encodeR at which an alarm condition has been corrected may be identified during scanning of said field encoders.

Claim 16

The invention as recited in claim 13 wherein each of said field encoders includes acknowledge pulse generating means for generating an acknowledge pulse when the shift register stage associated with each of said field encoders is energized, said control center includes counting means for receiving and counting said acknowledge pulses, and said cable means includes a wire common to each encoder for supplying said acknowledge pulses to said control center.

Claim 17

The invention as recited in claim 14 wherein said control center includes recording means connected with said counting means and said cable means to receive and record said alarm identification signals and said clear identification signals along with the count in said counting means whereby the field encoder producing an alarm identification pulse or a clear identification pulse is identified.

Claim 18

The invention as recited in claim 14 wherein said condition signal generating means in each field encoder includes means for providing analog signals representing conditions measured at said field encoders, said control center includes an analog-to-digital converter for receiving said analog signals and converting said analog signals into digital signals, means connecting said converter with said recording means to apply said digital signals thereto to record said digital signals along with the count in said counting means to identify the field encoder which produced the analog signals, and said cable means includes wires common to each field encoder to supply said analog signals to said converter.

Claim 19

The invention as recited in claim 16 wherein said control means includes shift pulse generating means, gating means having a plurality of inputs and an output connected with said shift pulse generating means for controlling the operation thereof, timing means for receiving said alarm identification signals and said clear identification signals and having an output connected with a first input of said gating means to inhibit said gating means for a predetermined time in response to the receipt of an alarm identification signal or a clear identification signal, and acknowledge pulse receiving means for receiving said acknowledge pulses and having an output connected with a second input of said gating means to prime said gating means after the receipt of an acknowledge pulse whereby a succeeding shift pulse is delayed if an acknowledge pulse in response to a preceding shift pulse is delayed or if an alarm identification signal or clear identification signal is received.

Claim 20

The invention as recited in claim 17 wherein a third input of said gating means is connected with said recording means and said converter to inhibit said gating means when said recording means or said converter is in operation.

Claim 21

The invention as recited in claim 18 wherein said control means includes clocking means for synchronizing the operation of said control means and permitting a shift pulse to be generated only after the elapse of a predetermined time after a preceding shift pulse.

Claim 22

The invention as recited in claim 19 wherein said means for providing analog signals in each field encoder includes time delay means for delaying said analog signals for a predetermined time longer than the predetermined time between shift pulses whereby a scan of said field encoders is not interrupted except by alarm identification signals and clear identification signals.

Claim 23

The invention as recited in claim 11 wherein said scan initiation means includes a second input for receiving scan request signals of a lower priority than said alarm signals and priority means for receiving said alarm signals and said lower priority signals and operating said scan initiation pulse generating means in accordance with the highest priority input.

Claim 24

The invention as recited in claim 21 wherein said control center includes means connected witH said control means for generating an end-of-scan pulse after all of said field encoders have been monitored to reset said control means, and said priority means includes means connected with said control means for generating a synthetic end-of-scan pulse to reset said control means and stop a scan in progress in response to the receipt of an alarm signal when the scan in progress was not initiated by an alarm signal.

Claim 25

The invention as recited in claim 14 wherein said control center includes field encoder preselect means connected with said counting means to provide an output when the number of acknowledge pulses counted by said counting means equals the number of the preselected field encoder, and said output is connected with said control means to interrupt the generation of shift pulses to permit conditions of the preselected field encoder to be monitored.