| 摘要 |
PURPOSE:To realize control between a center and a terminal device with data block constitution which has no waste by providing two kinds of error detecting means between both devices, and separating data between both of them into data for communication and data for control. CONSTITUTION:The terminal device 1 which generates transmission data and control data is connected to a data transmitter 3 equipped with two kinds of error detecting circuit through a transmission line 2 and then connected to a data network 5 through a transmission line 4. An error detection code B1 allows the 1st error detecting circuit to decide that three is no error, and an error detection code B2 allows the 2nd error detecting circuit in exclusive relation with the 1st error detecting circuit to decide that there is no error. For example, a polynomial X<16>+X<15>+X<2>+1 is used for the generation of the code B1, and a polynomial X<16>+X<12>+X<5>+1 is used for the code B2. Therefore, the 2nd error detecting circuit decides that the transmit data has an error and the 2nd error detecting circuit decides that the control data has an error. |
