WAGO I/O System 750 Series Manual page 125

The specialty modules represent 4x3 bytes input and output data and seize 4
Instances in Class (0x67) and 4 Instances in Class (0x68).
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 12 to maximally 48 bytes data
in both the Input and Output Process Image.
The first Input and output byte, which is assigned to an AS-interface master
module, contains the status / control byte, the second byte is 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 bytes contain the remaining process data.
The specialty modules represent 1x 12...48 bytes input and output data and
seize 1 Instance in Class (0x67) and 1 Instance in Class (0x68).
WAGO-I/O-SYSTEM 750
DeviceNet
Input and Output Process Image
Instance Byte Destination
C0/S0
n
-
D0
D1
Mailbox (0,6, 10, 12 or 18 bytes) /
D2
...
D46
I/O Modules • 125
Remark
Control/Status byte
Not used
Process data (0-32 bytes)