Specifications

CPU Memory: Data Types and Addressing Modes
5-4
S7-200 Programmable Controller System Manual
C79000-G7076-C233-01
Representation of Numbers
Table 5-1 shows the range of integer values that can be represented by the
different sizes of data.
Real (or floating-point) numbers are represented as 32-bit, single-precision
numbers whose format is: +1.175495E-38 to +3.402823E+38 (positive), and
-1.175495E-38 to -3.402823E+38 (negative). Real number values are accessed in
double-word lengths. Refer to ANSI/IEEE 754-1985 standard for more information
about real or floating-point numbers.
Table 5-1 Data Size Designations and Associated Integer Ranges
Dt Si
Unsigned Integer Range Signed Integer Range
Data Size
Decimal Hexadecimal Decimal Hexadecimal
B (Byte):
8-bit value
0 to 255 0 to FF -128 to 127 80 to 7F
W (Word):
16-bit value
0 to 65,535 0 to FFFF -32,768 to 32,767 8000 to 7FFF
D (Double word,
Dword):
32-bit value
0 to
4,294,967,295
0 to
FFFF FFFF
-2,147,483,648 to
2,147,483,647
8000 0000 to
7FFF FFFF
Addressing the Process-Image Input Register (I)
As described in Section 4.6, the CPU samples the physical input points at the
beginning of each scan cycle and writes these values to the process-image input
register. You can access the process-image input register in bits, bytes, words, or
double words.
Format:
Bit I [byte address].[bit address] I0.1
Byte, Word, Double Word I [size][starting byte address] IB4
Addressing the Process-Image Output Register (Q)
At the end of the scan cycle, the CPU copies the values stored in the
process-image output register to the physical output points. You can access the
process-image output register in bits, bytes, words, or double words.
Format:
Bit Q [byte address].[bit address] Q1.1
Byte, Word, Double Word Q [size][starting byte address] QB5