CONVERSION DEVICE, PERIPHERAL DEVICE, AND PROGRAMMABLE CONTROLLER

To output a waveform as quick as possible and enable debugging of an output waveform, a D/A conversion device 100 includes a waveform-data-string storage area 142 that stores therein a waveform data string including a plurality of digital values, a waveform-output-control-data storage area 144 in which operation-mode specifying data and update request data are written, a digital-value output unit 133 that, when the operation-mode specifying data specifies an automatic control mode, while sequentially updating an address to be read in the waveform-data-string storage area 142 for each output period set in advance, sequentially reads and outputs a digital value and that, when the operation-mode specifying data specifies a step execution mode or an output-address change mode, while updating the address to be read at a timing when the update request data is written, reads and outputs the digital value, and a D/A conversion unit 120 that converts the digital value output from the digital-value output unit 133 into an analog value.