There are many types of DIP switches. There are two main types of DIP switches. They are all decimal inputs, but the output is different. One is BCD code (ie, two-decimal) output, and the other is decimal output.

The most convenient to use as a human-machine interface is the dial switch of the decimal input / BCD code output. Each dial can represent a decimal number, and several decimal digits are required to select several pieces of BCD code dial stitching.

For example, four BCD dials can be combined to obtain a four-digit decimal input dial group. There are 5 contacts behind each BCD dial, where A is the input control line and the other 4 are the BCD code output signal lines.

When the dial is dialed to a different position, the input control line A is connected to one or several of the four BCD code output lines. The state of the BCD code output line that is connected to it is exactly the same as the decimal number indicated by the dial, and conforms to the second-decimal coding relationship.

The principle of the dial switch of decimal output is better understood. Each dial of this DIP switch also has 0-9 positions, and each position also has a corresponding digital display, which represents the decimal number of the dial input. There are 11 contacts behind the dial, of which A is the input control line and the other 10 are the output signal lines. When the dial is dialed to a different position, the input control line A is respectively connected to one of the 10 output lines, and can only be connected to one.