| 摘要 |
PURPOSE:To prevent the generation of synchronizing step-out between transmission and reception side apparatuses by transmitting characters coincident with the value of received telegram length as the characters of a data part when the telegram length different from a transmitted one is received. CONSTITUTION:When the value of telegram length transmitted from the transmission side apparatus 11 is changed any fault on a communication channel 12, the compared result of discordance is obtained by a comparing means 16. A control means 17 controls a transmission/reception means 15 based upon the compared result to set up the number of characters of the data part transmitted following the telegram length to the same value of the received telegram and to transmit respective characters in the data part by a value generating a parity error. Thereby, the generation of an error due to the difference between the received telegram length and the number of characters of the received telegram length can be removed on the reception side apparatus 13 and its reception frame is invalidated. Thus, the generation of the synchronizing step-out between the transmission and reception side apparatuses can be prevented. |
