244 Fieldbus Communication
WAGO-I/O-SYSTEM 750
750-882 Media Redundancy ETHERNET Controller
Manual
1.5.0
12.2.4 MODBUS Register Mapping
The following tables display the MODBUS addressing and the corresponding
IEC61131 addressing for the process image, the PFC variables, the NOVRAM
data, and the internal variables is represented.
Via the register services the states of the complex and digital I/O modules can be
determined or changed.
Register Access Reading (with FC3, FC4 and FC23)
Table 124: Register access reading (with FC3, FC4 and FC23)
MODBUS address
IEC 61131
Memory range
[dec]
[hex]
address
0...255
0x0000...0x00FF
%IW0...%IW255
Physical input area (1)
First 256 words of physical input data
256...511
0x0100...0x01FF %QW256...%QW511 PFC OUT area
Volatile PFC output variables
512...767
0x0200...0x02FF
%QW0...%QW255
Physical output area (1)
First 256 words of physical output data
768...1023
0x0300...0x03FF
%IW256...%IW511
PFC IN area
Volatile PFC input variables
1024...4095 0x0400...0x0FFF
-
MODBUS exception:
“Illegal data address”
4096...12287 0x1000...0x2FFF
-
Configuration register (see following
chapter “Configuration Functions“)
Not with FC23!
12288...24575 0x3000...0x5FFF %MW0...%MW12287 NOVRAM
24 kB retain memory *)
*) In Target settings RETAIN on 0, flags on
MAX (24 kB)
24576...25340 0x6000...0x62FC %IW512...%IW1275 Physical input area (2)
Additional 764 words physical input data
25341...28671 0x62FD...0x6FFF
-
MODBUS exception:
“Illegal data address”
28672...29435 0x7000...0x72FB %QW512...%QW1275 Physical output area (2)
Additional 764 words physical output data
29436...32767 0x72FC...0x7FFF
-
MODBUS exception:
“Illegal data address”
32768...36863 0x8000...0x8FFF
-
NOVRAM
"8 kB retain memory *)
*) In Target settings RETAIN on 0, flags on
MAX (32 kB)
36864...65535 0x9000...0xFFFF
-
MODBUS exception:
“Illegal data address”