Delta MS300 Series User Manual page 695

Chapter 16 PLC Function ApplicationsMS300
The following diagram shows the relationship between bits, digits, nibbles, words, and double words
in a binary system (see figure below).
BY3
NB7 NB6
Octal Number, OCT
The external input and output terminals of a DVP-PLC are numbered using octal numbers.
Example: External input:
External output:
Decimal Number, DEC
A PLC uses decimal numbers for the following purposes:
The setting values of timer T or counter C, such as TMR C0 K50 (K constant).

 The numbers of devices including M, T, C, or D, such as M10 or T30 (device number).
 An operand in an application command, such as MOV K123 D0 (K constant).
Binary Coded Decimal, BCD
Uses one nibble or four bits to express the data in a decimal number; a series of 16 bits can therefore
express a decimal number with four nibbles. These are used to read the input value of a rotating
numerical switch to input or output a numerical value to a seven-segment display drive.
Hexadecimal Number, HEX
A PLC uses hexadecimal numbers as operands in application commands, such as MOV H1A2B D0 (H
constant).
Constant K
PLC's usually prefixed decimal numbers with K, such as K100. This indicates that it is a decimal
number with a numeric value of 100.
Exceptions: You can combine K with a bit device X, Y, M, or S to produce data in the form of a nibble,
byte, word, or double word, such as in the case of K2Y10 or K4M100. Here K1 represents
a 4-bit combination, and K2–K4 represent 8-, 12-, and 16-bit combinations.
Constant H
PLC's usually prefixed hexadecimal numbers with H, such as in the case of H100. This indicates a
hexadecimal number with a numeric value of 100.
DW
W1
BY2
NB5 NB4
X0–X7, X10–X17... (Device number table);
Y0–Y7, Y10–Y17... (Device number table)
W0
BY1
NB3 NB2 NB1
Figure 16-51
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Double Word
Word
BY0
Byte
NB0
Nibble
Bit