Wago 750-841 PLC via Modbus to Ignition

Has anyone been able to successfully connect to a Wago 750-841 using the Modbus driver in Ignition? I configured it and it says it’s connected, but i don’t see any tags. My PLC is currently communicating with an ifix Scada using an iFix MBE driver. This is a Modbus Ethernet driver. Any suggestions?



What tags are you expecting to see? Nothing will be generated automatically - you will have to directly address the required registers by setting the OPC Item Path in a SQLTag e.g. [Device1]HR10 to read holding register number 10 (Modbus address 40010) from Device1.

Look at the User Manual under Gateway Configuration/OPC/Ignition OPC-UA Server/Drivers/Modbus Drivers/Modbus Ethernet/Addressing for more information.

You can also configure address mappings by following the [addresses] link next to the device you have configured.

Hello Marc,

You can have a quick setup video http://www.youtube.com/watch?v=DStcOXnAdo4.

Hope this can help

Hello Marc,

if you have connect the modbus-driver from Ignition to the Wago-PLC insert 5 variables to the Wago PLC:

var1 [color=#0040FF]AT [/color][color=#FF4000]%MW1000[/color] : [color=#0000FF]WORD;[/color] (Modbus-Adress 13288)
var2 [color=#0040FF]AT [/color][color=#FF4000]%MW1001[/color] : [color=#0000FF]WORD;[/color] (Modbus-Adress 13289)
var3 [color=#0040FF]AT [/color][color=#FF4000]%MW1002[/color] : [color=#0000FF]WORD;[/color] (Modbus-Adress 13290)
var4 [color=#0040FF]AT [/color][color=#FF4000]%MW1003[/color] : [color=#0000FF]WORD;[/color] (Modbus-Adress 13291)
var5 [color=#0040FF]AT [/color][color=#FF4000]%MW1004[/color] : [color=#0000FF]WORD;[/color] (Modbus-Adress 13292)

Upload the program to the Wago-PLC and start it.

Go to your Ignition-Modbus-Driver and click adresses, add a new row like this:
Prefix = test
Start = 0
End = 4
Step = false
Unit ID = 1
Modbus Type = HoldingRegister(Int16)
ModbusAdress = 13288
Radix = 10

Save it, open the Ignition Designer, add a new OPC-Tag from the OPC-UA Modbus-Device and check it.
If it don’t work correct, please check the modbus-device-driver, advanced-categories:
Use Zero Base Addressing = false
Reverse Numeric Word Order = false
Reverse String Byte Order = false
Right Justify Strings = false.


Thanks for all of the help guys! I was finally able to read data from the Wago. Now I have another question. I need to read in some string values from the PLC, but they are just coming in as a number.

I have the tag setup in the designer with a path as:
[RoomController] HRS12376:20
According to the user manual this should read modbus address 12376 at a length of 20.

I must be missing something, but I can’t see it. Any suggestions would be greatly appreciated!!

Thanks In Advance,


Your example: [RoomController] HRS12376:20

Wago PLC:

test_string [color=#0040FF]AT [/color][color=#BF40FF]%MW88[/color] : [color=#0040FF]STRING(20)[/color]; (Modbus-Adress 12376)

Ignition OPC-UA Modbus-Device:
Reverse String Byte Order = true

Tag setup in the designer:
[RoomController] HRS12376:20

This should be work.