188
•
Process Data Architecture for MODBUS/TCP
Specialty
Modules
WAGO-I/O-SYSTEM
750
ETHERNET TCP/IP
AS-interface Master Module
750-655
The length of the process image of the AS-interface master module can be set
to fixed sizes of 12, 20, 24, 32, 40 or 48 bytes.
It consists of a control or status byte, a mailbox with a size of 0, 6, 10, 12 or
18 bytes and the AS-interface process data, which can range from 0 to 32
bytes.
The AS-interface master module has a total of 6 to maximally 24 words data
in both the Input and Output Process Image. Word alignment is applied.
The first Input and output word, which is assigned to an AS-interface master
module, contains the status / control byte and one empty byte.
Subsequently the mailbox data are mapped, when the mailbox is permanently
superimposed (Mode 1).
In the operating mode with suppressable mailbox (Mode 2), the mailbox and
the cyclical process data are mapped next.
The following words contain the remaining process data.
Input and Output Process Image
Byte Destination
Offset
High Byte
Low Byte
Remark
0 - C0/S0 not
used
Control/Status
byte
1 D1 D0
2 D3 D2
3 D5 D4
... ... ...
max. 23
D45
D44
Mailbox (0, 3, 5, 6 or 9 words) /
Process data (0-16 words)
