Fieldbus controller 750-842
•
69
Data exchange
Modular I/O System
ETHERNET TCP/IP
3.2.5.2.3 Absolute
addresses
The direct display of individual memory cells (absolute addresses) in accordan-
ce with IEC 61131-3 is made using special character strings in accordance with
the following table:
Position
Character
Designation
Comments
1
%
Starts absolute address
2
I
Input
Q
Output
M
Flag
3
X*
Single bit
Data width
B
Byte (8 Bits)
W
Word (16 Bits)
D
Double word (32 Bits)
4
Address
* The character ‘X’ for bits can be deleted
Table 3.8: Absolute addresses
Note
Enter the absolute address character strings without blanks!
Example: Absolute addresses for input:
%IX14.
.15
.14
.13
.12
.11
.10
.9
.8
.7
.6
.5
.4
.3
.2
.1
.0
%IB29
%IB28
%IW14
%IDW7
* The character ‘X’ for single bits can be deleted
Table 3.9: Example for input absolute addresses
Address calculation (depending upon the word address):
Bit address:
word address .0 to .15
Byte address:
1. Byte: 2 x word address
2. Byte: 2 x word a 1
Dword address:
word address (even numbers) / 2
or
word address (uneven numbers) / 2, rounded off
