750-841 WAGO, 750-841 Datasheet - Page 64

• Manufacturer Part Number: 750-841
• Description: CONTR.ETHERNET TCP/IP 10/100MBIT
• Manufacturer: WAGO

Specifications of 750-841

• Rohs Compliant: YES
• No. Of Digital Inputs: 10
• No. Of Digital Outputs: 10

56 •
3.1.6.1 Memory Areas
Fieldbus Controller
Fieldbus Controller 750-841
(1) Reading data of the input modules is possible from both the controller’s
(2) In the same manner, writing data to output modules is possible from both
(3) The PFC input variables are written into the input memory space from the
(4) The variables processed by the controller’s CPU , via an IEC 61131-3
Fig. 3.1-8: Memory Areas and Data Exchange for a Fieldbus Controller
The PFC‘s process image contains the physical data of the I/O modules in
memory words 0 to 255 and 512 to 1275.
The controller’s process image also contains variables called “PFC Variables”.
These variables are allocated based on the fieldbus protocols. The MODBUS
TCP PFC variables are stored in memory from word 256 to 511. Ethernet IP
PFC variables are stored in memory from word 1276 to 1531. The memory
area above word 1531 is reserved for future protocols.
In addition, with the MODBUS TCP/IP protocol, all output data has a
mirrored image in memory with the address offset 0x0200 or 0x1000. This
fieldbus
master
CPU and from the fieldbus master (See Figure 3-8).
the controller’s CPU and from the fieldbus master.
fieldbus master and can be read by the controller’s CPU for further
processing.
application program, can be written to the PFC Variables and then read by
the fieldbus master.
Programmable Fieldbus Controller
for output data
memory area
for input data
memory area
word 0
word 511
word 255
word 0
word 255
word 511
word 256
word 256
modules
variables
modules
variables
4
output
2
output
input
input
PFC
PFC
1
1
4
2
3
3
CPU
IEC 61131-
program
WAGO-I/O-SYSTEM 750
ETHERNET TCP/IP
I/O modules
I
O
g012938e