What is D Code
D code refers to a draft code used in Gerber files to command a photoplotter. It serves as a command that controls the state of the light, determining whether it should be on or off, and also represents the position of the aperture on the list or wheel.
D codes in Gerber files have various purposes. The codes D01, D02, and D03 are specifically used to control the light state. D01 indicates that the light should be on for the next move, D02 indicates that the light should be off for the next move, and D03 represents a flash, where the light turns on and off after the move. It’s important to note that the effect of the flash is limited to the block in which it appears and is non-modal. Essentially, a D03 can be seen as a series of D02, D01, D02 commands linked together.
Additionally, D codes with values of 10 or higher are utilized to represent the position of the aperture on the list or wheel. However, unlike D01, D02, and D03 which have fixed meanings, D10 and higher values are assigned aperture shapes and dimensions by individual users. This means that the specific values and meanings of D Codes can vary depending on the user and the specific job requirements. For example, one job’s D10 could represent a 10 mil Round aperture, while another job’s D10 could represent a 45 mil Square aperture.