Technical data

Application Examples • 315
Visualization and Control Using SCADA Software
WAGO-I/O-SYSTEM 750
BACnet/IP Controller
Example for MODBUS function codes
The MODBUS function codes for National Instruments’ SCADA software
“Lookout,” employ 6-bit encoding. For example, with the first bit here repre-
senting the function code:
Tab. 8-10: Example for MODBUS Function Codes
Input code MODBUS function code
0 FC1 ( read coils Reading several input bits
1 FC2 ( read input discretes Reading several input bits
3 FC3 ( read multiple registers Reading several input registers
4 FC4 ( read input registers Reading a single input register
The subsequent five positions indicate the channel number for the consecu-
tively numbered digital or analog input or output channels.
Examples
• Read the first digital input: e.g., 0 0000 1
• Read the second analog input: e.g., 3 0000 2
Application example
The digital input channel 2 of the "Measured data" node can be read out by in-
putting "Measured data . 0 0000 2".
Fig. 8-1: Example of user software G012913e
Additional Information
For a detailed description of how to use a specific software, refer to the man-
ual included with the corresponding SCADA product.