WAGO 750-830 Manual page 63

3.1.6.1 Memory Areas
Fig. 3-8: Memory areas and data exchange
The controller process image contains the physical data for the bus modules
for MODBUS data. These have a value of word 0 ... 255 and word 512
...1275
#
$
The MODBUS PFC variables are stored in each of the memory areas for word
256 ... 511 between these sides.
%
&
The memory area for word 1276 ... 1531 is adjacent to the physical bus mod-
ule data. This area is reserved and may not be used by the user. The subse-
quent memory area, starting from word 1532, is reserved for future protocol
expansion and other PFC variables.
WAGO-I/O-SYSTEM 750
BACnet/IP Controller
Programmable Fieldbus Controller
memory area
for input data
word 0
word 255
word 256
word 511
word 512
word 1275
fieldbus
memory area
master
for output data
word 0
word 255
word 256
word 511
word 512
word 1275
The data of the input modules can be read by the CPU and from the field-
bus side.
In the same manner, writing to the output modules is possible from the
CPU and from the fieldbus side.
The MODBUS PFC input variables are written to the input memory area
from the fieldbus side and read in by the CPU for processing.
The variables processed by the CPU via the IEC -61131-3 program are
filed in the output memory space and can be read out by the master.
BACnet/IP Controller 750-830
input
modules
MODBUS
PFC - IN -
variables
input
modules
CPU
output
modules
MODBUS
PFC - OUT -
variables
output
modules
Data Exchange
I/O modules
IEC 61131
program
• 63
g015038d