2 Functions of Devices in DVP-PLC explanations bellows for the functions and works of every type of value. 1. Binary value (BIN) All the operations and storage of values in PLC are conducted in BIN. Belows are the terms for BIN values. Bit, nibble, byte, word, and double word in a binary system: DW Double Word W1 W0 Word BY3 BY2 BY1 BY0 Byte NB0 NB1 NB2 NB3 NB4 NB5 NB6 NB7 Nibble Bit 2. Octal value (OCT) The No. of external input and output terminals in DVP-PLC is numbered in octal system. For example: External input: X0 ~ X7, X10 ~ X17…(device No.) External output: Y0 ~ Y7, Y10 ~ Y17…(device No.) 3. Decimal value (DEC) Occasions of using decimal values in DVP-PLC:
Set value in timer T and counter C, e.g. TMR C0 K50 (constant K) No. of device S, M, T, C, D, E, F, P, I, e.g. M10, T30. (device No.) Operands in application instructions, e.g. MOV K123 D0 (constant K) 4. Binary code decimal (BCD) A decimal datum is presented by a nibble or 4 bits. Therefore, a continuous 16 bits can be presented as a 4-digit decimal value. BCD is mainly used on reading the input value from the DIP switch or the data output to a 7-section display. 5. Hexadecimal value (HEX) Occasion of using hexadecimal values: Operands in application instructions, e.g. MOV H1A2B D0 (constant H) Constant K: “K” is normally placed before a decimal value in the PLC.
For example, K100 refers to a decimal value, 100. DVP-PLC Application Manual 2-9 Bit: The basic unit for a BIN value, either 1 or 0. Nibble: Composed of 4 continuous bits (e.g. b3 ~ b0). Presented as the decimal value 0 ~ 9 of a digit or 0 ~ F in hex. Byte: Composed of 2 continuous nibble (i.e. 8 bits, b7 ~ b0). Presented as 00 ~ FF in hex. Word: Composed of 2 continuous bytes (i.e. 16 bits, b15 ~ b0). Presented as 4-digit 0000 ~ FFFF in hex. Double wo rd: Composed of 2 continuous words (i.e. 32 bits, b31 ~ b0). Presented as 8 digit 00000000 ~ FFFFFFFF.