| 摘要 |
PROBLEM TO BE SOLVED: To provide a communication apparatus which can communicate a digital signal normally, even when drastic changes in a process value are caused which can change an output level of an analog signal largely during communication of the digital signal.SOLUTION: A communication apparatus 1 includes: a difference calculation circuit 21 for calculating a difference between an output value P1 which defines the output level of an output signal S3 transmitted through a two-wire type transmission line L and a process value P2 which defines the output level of the output signal S3 to be transmitted through the transmission line L; a selector 25 for selecting the process value P1 when the difference calculated by the difference calculation circuit 21 is equal to or lower than a limit value LM which defines the maximum change amount of the output level which is permitted by the output signal S3 and selecting an output value P3 which changes the output level of the output signal S3 by the maximum change amount when the difference is larger than the limit value LM; and an I/F section 30 for transmitting the output signal S3 having an output level according to the output value which is selected by the selector 25, to the transmission line L. |
