Technical data

70 • Fieldbus Controller 750-841
Data Exchange
WAGO-I/O-SYSTEM 750
ETHERNET TCP/IP
Adding an offset of 0x0200 to the MODBUS output address lets you read back
output data.
Note
For MODBUS mapping, all output data over 256 words resides in the
memory area 0x6000 to 0x62FC, and can be read back with an offset of
1000
hex
(0x1000) added onto the MODBUS address.
0x0000
0x00FF
0x0000
(0x0200)
00x0FF
(0x02FF)
0x6000
0x62FC
0x6000
(0x7000)
0x62FC
(0x72FC)
PII = Process Input
Image
PIO = Process Output
Image
MODBUS master
PII
PIO
I/O modules
Inputs
Outputs
Programmable Fieldbus Controller
Fig. 3-9: Data exchange between MODBUS master and I/O modules g015045e
The MODBUS register assignments allow for a Fieldbus Master to read and
write data from the controller. The register mapping for IEC 61131.1 varies
from the MODBUS assignments. Please refer to section 3.1.5.6.2 for a
comparison of MODBUS TCP and IEC 61131.1 address mapping.