the receive count flag does not match the flag in the received control character in line 8 the rtx1 is also echoed back to the transmit pl in line 8 in line 9 the rtx1 is correctly received by the transmit pl which causes the transmit pl to retransmit the character k from the holding register while these few tables do not show all of the possible scenarios for receiving and correcting data it should be apparent to one of ordinary skill in the art how the flow charts of fig6 and 7 are used to correct other types of errors it will be understood that the data transmission over each channel and time slot is a full duplex transmission this means that information can be traveling in each direction in the case of the network according to fig1 the concentrator 30 might be sending information to terminal 48 while the terminal is simultaneously sending information back to the concentrator 30 each time slot includes a transmission byte and an echo byte if the concentrator is sending an 34 ab 34 to the terminal while the terminal is sending 34 yz 34 to the concentrator the flow of information will be as shown in table 7 table 7______________________________________concentrator terminaldata echo data.