Analog Input Modules - WAGO 750-872/020-000 Manual

216 • Process Data Architecture for MODBUS/TCP

Analog Input Modules

5.2.3 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)
Byte Destination
Offset
High Byte
0 D1
1 D3
Byte Destination
Offset
High Byte
0 D1
1 D3
Input Process Image
Low Byte
D0
D2
Input Process Image
Low Byte
D0 Measured Value Channel 1
D2 Measured Value Channel 2
Remark
Measured Value U
D
Measured Value U
ref
Remark
WAGO-I/O-SYSTEM 750
ETHERNET TCP/IP