Analog Input Modules - WAGO 750 Series Manual

7.2.3 Analog Input Modules

The hardware of an analog input module has 16 bits of measured analog
data per channel and 8 bits of control/status. However, the
coupler/controller with MODBUS/TCP does not have access to the 8
control/status bits. Therefore, the coupler/controller with MODBUS/TCP
can only access the 16 bits of analog data per channel, which are grouped
as words and mapped in Intel format in the Input Process Image.
When digital input modules are also present in the node, the analog input
data is always mapped into the Input Process Image in front of the digital
data.
1 Channel Analog Input Module
750-491, (and all variations)
2 Channel Analog Input Modules
750-452, -454, -456, -461, -462, -465, -466, -467, -469, -472, -474, -475,
-476, -477, -478, -479, -480, -481, -483, -485, -492, (and all variations),
753-452, -454, -456, -461, -465, -466, -467, -469, -472, -474, -475, -476, -
477, -478, -479, -483, -492, (and all variations)
WAGO-I/O-SYSTEM 750
Linux Fieldbus Coupler
Byte Destination
Offset
High Byte
0 D1
1 D3
Byte Destination
Offset
High Byte
0 D1
1 D3
Process Data Architecture for MODBUS/TCP
Input Process Image
Low Byte
D0
D2
Input Process Image
Low Byte
D0 Measured Value Channel 1
D2 Measured Value Channel 2
I/O Modules • 151
Remark
Measured Value U
D
Measured Value U
ref
Remark