How Program Functions Handle Numerical Data; Data Types - GE PACSystems RXi User Manual

Chapter 7. CPU Program Data

How Program Functions Handle Numerical Data

7.8
Regardless of where data is stored in memory – in one of the bit memories or one of the word
memories – the application program can handle it as different data types.
7.8.1

Data Types

Type Name
BOOL Boolean
BYTE Byte
WORD Word
DWORD Double Word
UINT Unsigned
Integer
INT Signed
Integer
DINT Double
Precision
Integer
REAL Floating Point Uses 32 consecutive bits (two consecutive 16-bit
LREAL Double
Precision
Floating Point
BCD-4 Four-Digit
BCD
136
Description
The smallest unit of memory. Has two states, 1 or 0. A
BOOL array may have length N.
Has an 8-bit value. Has 256 values (0–255). A BYTE
array may have length N.
Uses 16 consecutive bits of data memory. The valid
range of word values is 0000 hex to FFFF hex.
Has the same characteristics as a single word data
type, except that it uses 32 consecutive bits in data
memory instead of only 16 bits.
Uses 16-bit memory data locations. They have a valid
range of 0 to +65535 (FFFF hex).
Uses 16-bit memory data locations, and are
represented in 2's complement notation. The valid
range of an INT data type is –32768 to +32767.
Stored in 32-bit data memory locations (two consecutive
16-bit memory locations). Always signed values (bit 32
is the sign bit). The valid range of a DINT data type
is -2147483648 to +2147483647
memory locations). The range of numbers that can be
stored in this format is from ±1.401298E-45 to
±3.402823E+38. For the IEEE format, refer to Section
7.8.2, Floating Point Numbers.
Uses 64 consecutive bits (four consecutive 16-bit
memory locations). The range of numbers that can be
stored in this format is from ±2.2250738585072020E-
308 to ±1.7976931348623157E+308. For the IEEE
format, refer to Section 7.8.2, Floating Point Numbers.
Uses 16-bit data memory locations. Each binary coded
decimal (BCD) digit uses four bits and can represent
numbers between 0 and 9. This BCD coding of the 16
bits has a legal value range of 0 to 9999.
PACSystems* RXi Distributed IO Controller User Manual
Data Format
Register
(16 bit states)
1
16 1
Register 2 Register 1
32 17 16
(32 bit states)
Register
(Binary value)
1
16 1
(Two's
Register 1
Complement
S
value)
16 1
s=sign bit (0=positive,
1=negative)
Register 2 Register 1
s
32 17 16 1
(Binary value)
s=sign bit (0=positive,
1=negative)
Register 2 Register 1
32 17 16
(IEEE format)
Register 2 Register 1
32 17 16
Register 4 Register 3
64 49 48
(IEEE format)
Register 1
(4 BCD digits)
4 3 2 1
13 9 5 1
GFK-2816F
1
1
1
33