Interrogation device
First Claim
1. An interrogation unit for connecting into an installation via sensing elements connected to sense required information in the installation, said interrogation unit having signal supplying means for supplying signals indicative of the condition of each of various sensors in the installation, and trigger circuit means activatable upon recipt of a request signal to transmit said signals for each of the sensors in turn, said signal supplying means including tone generating means which generates two different tones and being connected to either transmit said tones or not to transmit said tones, whereby to indicate that any particular sensor has changed from its initial condition or not, a first of said tones being used for identifying a group of sensors whilst the second of said tones being used for identifying particular sensors in that group.
1 Assignment
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Accused Products
Abstract
An interrogation unit for connecting into an installation via sensing elements connected to sense required information in the installation, said interrogation unit having signal supplying means for supplying signals indicative of the condition of each of various sensors in the installation, and trigger circuit means activatable upon receipt of a request signal to transmit said signals for each of the sensors in turn.
32 Citations
10 Claims
- 1. An interrogation unit for connecting into an installation via sensing elements connected to sense required information in the installation, said interrogation unit having signal supplying means for supplying signals indicative of the condition of each of various sensors in the installation, and trigger circuit means activatable upon recipt of a request signal to transmit said signals for each of the sensors in turn, said signal supplying means including tone generating means which generates two different tones and being connected to either transmit said tones or not to transmit said tones, whereby to indicate that any particular sensor has changed from its initial condition or not, a first of said tones being used for identifying a group of sensors whilst the second of said tones being used for identifying particular sensors in that group.
- 9. An interrogation unit for connecting into an installation via sensing elements connected to sense required information in the installation, said interrogation unit having signal supplying means for supplying signals indicative of the condition of each of various sensors in the installation, and trigger circuit means activatable upon receipt of a request signal to transmit said signals for each of the sensors in turn, wherein said signal supplying means include tone generating means which is connected to either transmit said tone or not to transmit said tone, whereby to indicate that any particular sensor has changed from its initial condition or not, and wherein said tone generating means generates two different tones, a first of said tones being used for identifying a group of sensors whilst the second of said tones being used for identifying particular sensors in that group, said signal supplying means providing N bursts of said second of said tone signals for sensor N, and N+1 bursts for sensor N+1, whereby to identify sensors in the transmission by counting the number of tone bursts.
Specification