| 摘要 |
PROBLEM TO BE SOLVED: To provide an analog output device that can simply diagnose itself with high reliability at a low cost even when the circuit is in operation. SOLUTION: A channel in which a digital/analog converter 21 is provided is referred to as a channel ch1 and a channel in which a digital/analog converter 22 is provided is referred to as a channel ch2. When a CPU instructs diagnosis of a prescribed channel (the ch1 is selected), the other channel not being a diagnosis object is a comparison channel (the ch2 is selected). A digital signal with the same value as that of the diagnosis object channel is given to the digital/analog converter 22 of the comparison channel, a comparator circuit 51 compares an output of the digital/analog converter 22 with an output of an output buffer 31 in the diagnosis object channel to discriminate that there is a fault in the diagnosis object channel when they have a prescribed difference level.
|
