Method and system for data transmission

摘要

Herein disclosed is a data communication system in which a plurality of node equipments are linked to a common signal transmission line so that the data may be communicated between the respective node equipments. The data communication system is characterized: in that at least one of the node equipments includes means for generating and transmitting repeatedly for a predetermined period the channel which contains a data transmission bit and a validity bit for the former bit; and in that each of the node equipments linked to the common signal transmission line partly sends out the data through said channel and partly makes the validity indicating bit indicate an invalid state, when the speed of said data is so slower than the predetermined period of said channel that the data to be sent out for the predetermined period are out of time thereby to make it possible to effect the data transmission at an arbitrary speed shorter than said predetermined period. Herein also disclosed is a data communication system in which a plurality of node equipments are jointed by a common transmission loop line and in which the information of multiple channels is repeatedly transmitted for a predetermined period to said transmission loop line so that the channel information may be sent and received between terminal equipments linked to said node equipments. The data communication system is characterized in that an identical pattern for synchronization is inserted into and transmitted by the plural head channels of each period so that the synchronization is effected at each of said node equipments by detecting the synchronizing pattern received by means of a detecting circuit.