Honeywell G.m.b.h.

Darrell Chelcun

Lawrence J Dressel

Bruce D Westphal

James A Berardi

A transceiver circuit for connecting a data processing unit to a communication bus, wherein said data processing unit is capable of transmitting, receiving and processing non-return to zero (NRZ) signals having a normally high level and assuming a low level to indicate a data bit and said communication bus is capable of transmitting a pulse-no pulse signal to indicate data bits, is disclosed having an input connected to the data processing unit for receiving the non-return to zero signals, a triggering circuit which is responsive to a leading edge of a non-return to zero signal to supply triggering pulses having a predetermined frequency, a gating circuit for passing through the triggering pulses as long as the non-return to zero signal is at a predetermined level, and a pulse-no pulse circuit responsive to the triggering pulses for supplying the pulse-no pulse signals to the communication bus. In addition, the receive portion of the transceiver circuit is responsive to the pulse-no pulse signals to convert them into non-return to zero signals.

Data processing protocol system

A protocol system for data processing equipment, particularly equipment used in building automation monitoring and control systems for air-conditioning control and monitoring of fire and security points is disclosed having a plurality of stations connected to a data bus, each station having an apparatus for monitoring the traffic on the data bus, calculating its turn to transmit or time slot during which it is permitted to transmit data on the bus and updating its calculated turn or time slot after each station designated to transmit in a turn or time slot after each station designated to transmit in a turn before it has transmitted data. Although each station has a designated time slot during which it may transmit, each time slot is of variable duration depending upon the extent of data to be transmitted. Thus, each station must be capable of calculating its time slot after each previous station has either transmitted or failed to transmit, and this station must calculate its own time slot accurately even though each previous station has transmitted for a variable length of time.

Growing community of inventors

Boling Brook, IL, United States of America

Darrell Chelcun