Technical data

260 • I/O Modules
Process Data Architecture for MODBUS/TCP
WAGO-I/O-SYSTEM 750
BACnet/IP Controller
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 ana-
log 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)
Input Process Image
Byte Destination
Offset
High Byte Low Byte
Remark
0 D1 D0 Measured Value U
D
1 D3 D2 Measured Value U
ref
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)
Input Process Image
Byte Destination
Offset
High Byte Low Byte
Remark
0 D1 D0 Measured Value Channel 1
1 D3 D2 Measured Value Channel 2