Communication technique

Claim 2

A communication system comprising: a source of binary signals including an ''''end-of-transmission'''' signal, transmitting means for transmitting said binary signals, first adder means for adding the signals transmitted to develop a check sum signal comprising the sum of the binary signals transmitted by said transmitting means including said ''''end-oftransmission'''' signal, logic means causing said transmitting means to transmit said check sum signal from said first adder means, upon detection by said logic means of said ''''end-of-transmission'''' signal being transmitted by said transmitting means, receiver means for receiving said binary signals and said check sum signal from said transmitting means, and second adder means for adding the binary signals received by said receiver means to develop a received sum signal.

Claim 3

The system of claim 1 further comprising: comparison means connected to receive said check sum signal and serving to compare said check sum signal with said received sum signal, receiver logic means causing said receiver means to transmit said binary signals to said second adder means and said check sum signal to said comparison means, and means for indicating the results of said comparison.

Claim 4

The system of claim 1 wherein said first and second adder means each comprise: means for converting said binary signals to data words, a register for storing a data word, an adding circuit having full carry propagation for receiving a data word from said converting means and adding said data word to any data word contained in said register to obtain a complete total in said register.

Claim 5

The system of claim 3 wherein said converting means comprises: a series-to-parallel converter for receiving said binary signals in serial form, converting said binary signals to data words in parallel form, and inserting said data words in parallel form into said adding circuit.

Claim 6

A communication method comprising the steps of: transmitting a plurality of binary signals including an ''''end-of-transmission'''' signal, adding the binary signals transmitted to obtain a check sum comprising a total of the transmitted signals including said ''''end-of-transmission'''' signal, transmitting said check sum only upon transmitting said ''''end-of-transmission'''' signal, receiving the transmitted binary signals, adding the binary signals received to obtain a received signal sum, and comparing said received signal sum with said check sum to verify the integrity of the transmission.

Claim 7

A communication method comprising the steps of: transmitting a plurality of binary signals including an ''''end-of-transmission'''' signal, adding the binary signals transmitted to obtain a check sum comprising a total of the transmitted signals including said ''''end-of-transmission'''' signal, transmitting said check sum only upon transmitting said ''''end-of-transmission'''' signal, receiving the transmitted binary signals, adding the binary signals received to obtain a received signal sum, and comparing said received signal sum with said check sum to verify the integrity of the transmission.

Claim 8

An automatic control system for material handling equipment comprising: a computer generating binary command signals including an ''''end-of-transmission'''' signal, a material handling device to be controlled by said computer, first transceiver means connected to said computer to transmit said command signals, check sum generating means connected to add said command signals to develop a check sum signal of the total transmitted command signals including said ''''end-of-transmission'''' signal and to cause said first transceiver to transmit said total of said check sum signal immediately subsequent to transmission of said ''''end-of-transmission'''' signal, second transceiver means carried by said material handling device for receiving said command signals and said check sum signal and serving to add said command signals to develop a received sum signal of the total received command signals, and comparison means connected to said second transceiver and serving to compare said total of said transmitted check sum signal wiTh said total of said received sum signal.

Claim 9

An automatic control system for material handling equipment comprising: a computer generating binary command signals including an ''''end-of-transmission'''' signal, a material handling device to be controlled by said computer, first transceiver means connected to said computer to transmit said command signals, check sum generating means connected to add said command signals to develop a check sum signal of the total transmitted command signals including said ''''end-of-transmission'''' signal and to cause said first transceiver to transmit said total of said check sum signal immediately subsequent to transmission of said ''''end-of-transmission'''' signal, second transceiver means carried by said material handling device for receiving said command signals and said check sum signal and serving to add said command signals to develop a received sum signal of the total received command signals, and comparison means connected to said second transceiver and serving to compare said total of said transmitted check sum signal wiTh said total of said received sum signal.