Peripheral station in an information handling system

Claim 1

For use in a communication system having a signal bus, a master station, and a plurality of peripheral stations controlled by signals transmitted on the signal bus by the master station in a time division multiplex manner, the signals being transmitted cyclically in information frames with the information frame for each peripheral station occupying a given position in the cycle, an improved peripheral station comprising: address decoding means for identifying an information frame for said peripheral station and for generating an enable signal in response thereto, said decoding means including means for setting an address and a counter for counting information frames, said address setting means and said counter being used in identification of said information frame; gating means for coupling signals from said signal bus to one or more outputs of said peripheral station in response to said enable signal; verifying means interposed between said gating means and said one or more outputs, said verifying means being arranged to store each gated signal, compare it with the corresponding gating signal resulting from the information frame received by the peripheral station during the next cycle of transmitted signals, and allowing said one or more outputs to change when the compared signals agree; and sync detector means for detecting synchronizing (sync) signals on said signal bus, for comparing the occurrence of said sync signals with the count held in said counter, and for disabling said verifying means on the detection of a lack of synchronism between the signals on said signal bus and said address decoding means.