초록 ▼

A monitor/control communication net with intelligent peripherals, that is, peripherals which are capable of monitoring and/or controlling various devices in accordance with messages received from a central panel cpu and which are also capable of reporting to the central panel the status of one or mo

A monitor/control communication net with intelligent peripherals, that is, peripherals which are capable of monitoring and/or controlling various devices in accordance with messages received from a central panel cpu and which are also capable of reporting to the central panel the status of one or more devices monitored by the peripheral. Each peripheral is assigned a unique address by which it is polled by the central panel. All communication messages between the central panel and peripherals include a format code which indicates the nature of the message and the length of any data field in the message. Communication time is minimized by permitting the data field to vary in length from one peripheral to another, depending on the number and type of devices being monitored and/or controlled by the peripherals.

대표청구항 ▼

Communication net comprising a pair of communication lines, at least one peripheral device connected to said communication lines including means for receiving a general poll digital message transmitted on said communication lines which message includes a first format code identifying the message as

Communication net comprising a pair of communication lines, at least one peripheral device connected to said communication lines including means for receiving a general poll digital message transmitted on said communication lines which message includes a first format code identifying the message as a general poll and an address uniquely identifying the peripheral, means for validating said format code and address, means for monitoring the outputs of one or more devices connected to the peripheral, means for detecting a change in any of said outputs, and means for transmitting a digital message on said communication lines if a change has been detected in said outputs, said last-mentioned message including a second format code, an address identical to said address received by the peripheral, and a data field which indicates the status of said monitored outputs, and wherein said second format code indicates the length of said data field.