You can set conditions for channels with string values on the String values tab:

1. In the Value column, specify the text value of a channel.
   

2. In the Mode column, select an action that happens when a channel accepts a specified value. 

   State	Channel state change on the map
   Event	Event generation
   Both	Channel state change and event generation

3. In the Event text column, enter a message that is sent when a channel accepts a specified value. 
4. Click the Apply button.