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 af...

A distributed data processing system including a general, passive, communications network, and a plurality of local systems which each have a central processing unit, associated memory, and at least one peripheral device. The control of the intercommunication is effected by respective system intercommunication processors, each interfacing one local system to the network. Each systems intercommunications processor is attached to the network by means of a respective communication module. A communi...

Network interface software for use in a network of computers includes software providing protocols for transmission of messages without high level software acknowledgments required. Negative acknowledgments are relied on to indicate the failure of complete message reception.

A local area network control apparatus is interposed between a host computer whose main storage stores an appropriate number of user programs and a plurality of interactive termials which have protocols of any desired level. The apparatus comprises a program module which has a predetermined bypass function, a program module which has a function of executing a specified protocol, and a control table in which names of the user programs to be handled, designations of the interacting terminals there...

Secondary storage subsystems exchange messages and data with host data processing systems and also forward messages between host systems. Host systems thereby communicate with each other in addition to having access to data in subsystem storage. Access to subsystem storage is initiated by a "request" sent from a host to the subsystem. Each request is a message containing an array of one or more commands, each command specifying a transfer of data or a control function to be performed by the subs...

A communication adapter circuit (10) is connected to a processor through processor I/O interface buses (12, 14). Data and control signals are provided through the buses (12, 14) to a timer circuit (18), a programmable peripheral interface circuit (20), an asynchronous and bisynchronous control circuit (22) and an SDLC/HDLC control circuit (24). Each of the control circuits (22, 24) includes parallel-to-serial and serial-to-parallel conversion circuitry. A clock select circuit (32) operates in co...

A battery powered receiver including a adaptive signal decoder is disclosed which is capable of processing detected encoded signals in accordance with a plurality of decoding schemes. The decoder has an equivalent microcomputer implementation. Energy conservation means operating independently of the detected signals acts to conserve the energy of the battery.

The bit streams, transporting the frames, received from lines (6) are placed in register 12 in such a way that n bits are processed in parallel during a time interval T. Parallel processor 10 counts the consecutive logical "1" bits beginning at the low order (left most) bit of the n bits received in interval T and from the bits received in the previous interval T-1, to determine when this number is found equal to 5 which bits have to be deleted, and when this number is found equal to 6 whether a...

An apparatus is provided for controlling the transfer of data between first and second service processors; wherein the respective first and second service processors are adapted to provide respective transfer instructions requesting such data transfers, the apparatus comprising: first lines for conducting digital signals; second lines for conducting digital signals; first integrated circuit for providing digital signals to said first lines in response to first control signals and for receiving d...

An improved, distributed network comprising a central server and at least one foreign server, which provides a method and means for integrating multiple networks with varying file systems is provided. The present invention allows foreign servers to coexist on a single integrated file server while eliminating server-to-server translations, thus improving the performance of the network. In a preferred embodiment, the central server communicates with central server clients in accordance with a cent...