Abstract The multiplex system comprises a central controller (20) and a plurality of remote stations (50) interconnected with the central controller (20) by means of a cable (90). The central controller (20) repeatedly polls the remote stations (50), to cause them to generate response signals (R). The response signals (R) are counted by an integration counter in the central controller (20) which stores the count which is incremented when a response signal value is in a logic low state and is decremented when a response signal value is in a logic high state. The count is compared with a threshold value. The polled response signal is classified as being in the logic low state when the count is greater than or is equal to the threshold value and the count is set to an intermediate value less than the threshold value when the polled response signal is classified as being in the logic low state. The fact that the polled response signal has been classified is indicated when the count reaches a reset value which is less than the intermediate value.
A multiplex system (10) comprising a central controller (20); a plurality of remote stations (50) interconnected with the central controller (20) by means of a cable (90); means (70) included in a first one of the remote stations (50) for generating a response signal (R); and means (23) included in the central controller (20), for repeatedly polling the response signal to determine a set of response signal values; characterized by an integration counter included in the central controller (20) and being operative to store a response signal count; means for incrementing the count each time a response signal value is in a logic low state; means for decrementing the count each time a response signal value is in a logic high state; means for comparing the count with a threshold value; means for classifying the polled response signal as being in a logic low state when the comparing means indicates that the count is greater than, or equal to, the threshold value; means for setting the count to an intermediate value which is less than the threshold value when the classifying means classifies the polled response signal as being in the logic low state; and means for indicating that the polled response signal has been classified by the classifying means when the count reaches a reset value which is less than the intermediate value.
Claim 2
Dependent Claim
224 words
A multiplex system (10) comprising a central controller (20); a plurality of remote stations (50) interconnected with the central controller (20) by means of a cable (90); means (70) included in a first one of the remote stations (50) for generating a response signal (R); and means (23) included in the central controller (20), for repeatedly polling the response signal to determine a set of response signal values; characterized by an integration counter included in the central controller (20) and being operative to store a response signal count; means for incrementing the count each time a response signal value is in a logic low state; means for decrementing the count each time a response signal value is in a logic high state; means for comparing the count with a threshold value; means for classifying the polled response signal as being in a logic low state when the comparing means indicates that the count is greater than, or equal to, the threshold value; means for setting the count to an intermediate value which is less than the threshold value when the classifying means classifies the polled response signal as being in the logic low state; and means for indicating that the polled response signal has been classified by the classifying means when the count reaches a reset value which is less than the intermediate value.
Claim 3
Dependent Claim
33 words
A multiplex system according to claim 1, characterized in that the decrementing means decrements the count by a predetermined amount, and in that the incrementing means increments the count by said predetermined amount.
Claim 4
Dependent Claim
56 words
A multiplex system according to claim 1 or 2, characterized in that the remote stations (50) comprise keyboards (70) each having a plurality of row conductors (72) and a plurality of column conductors (74) and an array of switches (76) each positioned to interconnect a respective row conductor (72) with a respective column conductor when activated.
Claim 5
Dependent Claim
30 words
A multiplex system according to claim 1, 2 or 3, characterized in that response bits of the response signal (R) are interleaved with commands bits of a command signal (C).
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.