Hi,

if you need to change values via the web-server, then you have to allow to change parameters from a FB.
+ Check the FB properties if protect is not enabled (protects the value for parametermode)
+ Check the properties of the message text if (protects the parameter in message text. In paramerter mode you can change)

If you want to change values in VM-Memory, then use the variable table in the Web-Server, enter the VM-Adress and change the value

If you have several LOGO! 8 in a network and you can't access to LOGO!, then check:

+ in same subnet: If the IP of the LOGO! is correct
+ in different subnet: If the subnet is configured right

Attached is a example with different protection and VW0 you can change via Web-Server.

Hope this helps