Omron NX-series User Manual page 193

First byte +
(integer multiple of 2)
First byte +
(integer multiple of 2)
Variables with Four-byte Alignments (e.g., DWORD)
Four bytes of memory are allocated for the four-byte alignment.
The location of the first byte of data in memory is an integer multiple of four bytes. Therefore, if a varia-
ble with a two-byte alignment, such as WORD data, is inserted, two bytes of unused memory will re-
main.
Example: Consecutive variables in the following order: DWORD, WORD, and DWORD
First byte +
(integer multiple of 4)
First byte +
(integer multiple of 2)
First byte +
(integer multiple of 4)
Variables with Eight-byte Alignments (e.g., LWORD)
Eight bytes of memory are allocated for the eight-byte alignment.
The location of the first byte of data in memory is an integer multiple of eight bytes. Therefore, if a
variable with a two-byte alignment, such as WORD data, is inserted, six bytes of unused memory will
remain. If a variable with a four-byte alignment, such as DWORD data, is inserted, four bytes of un-
used memory will remain.
Example: Consecutive variables in the following order: LWORD, WORD, and LWORD
NX-series Communication Control Unit Built-in Function User's Manual (Z396)
Memory
Bytes
First byte
First byte + 1
First byte + 2
First byte + 3
Memory
Bytes
First byte
First byte + 1
First byte + 2
First byte + 3
First byte + 4
First byte + 5
First byte + 6
Not used.
First byte + 7
First byte + 8
First byte + 9
First byte + 10
First byte + 11
Variable Table
Name
A
Variable A, 2 bytes
B
Variable B, 2 bytes
Variable Table
Name Data type
A DWORD
B WORD
Variable A,
C DWORD
4 bytes
Variable B,
2 bytes
Variable C,
4 bytes
Appendices
Data type
BOOL
BOOL
A - 19
A