BCD special characters
1. Introduction
This Technical Application Node explains the basics of the BCD code and how special characters can be set and used in our handheld.
2. BCD code
BCD code stands for binary-coded decimal, i.e. dual-coded decimal digit. Each decimal digit 0 to 9 is represented by four bits (0000 to 1001 or 0x0...0x9). Another designation is 8-4-2-1-BCD code.
This makes it possible to represent a 4-digit number with only two bytes using the BCD code instead of the four bytes required with integer or ASCII.
3. BCD special characters in the handheld
As only the bits from 0000 to 1001 (0x0...0x9) in the half-byte are used for the binary representation of the digits, the range 1011 to 1111 (0xA...0xF) can be used for special characters.
Three special characters can currently be used in the RFID handheld. The BCD special characters [+], [-] and [.] can be freely assigned to the values 0xA...0xF in the settings. The assignment is global and applies to all templates.
The characters A to F correspond to the values 0xA...0xF.
With the special characters, it must be ensured that [+] and [-] may only be at the beginning of the character string. The HF/LF RFID app does not allow these characters to be entered in the middle of a character string.
[.] can be located anywhere in the character string and is generally used to represent a decimal number with a comma in the BCD code.