There are times when it is useful to be able to display the source that is routed to a particular output, or even vary the settings of devices based on the current routing. To do this we use a special function in the Lua programming language that is built-in to Helm.
Here’s an example panel

1. Source select router bus group
2. Destination select router output bus
3. Router device
4. A text label that will show what source is currently routed to output 1
We use the router Tally Change Event Script

out1_src = helm.getRouterSource("DUMMYRTR_1","0","0"); helm.set("LABEL_1","Text",out1_src);
This can only be done in Lua using the function helm.getRouterSource. The syntax for this call is:helm.getRouterSource(<router name>,<output number>,<level>)Note: the router name should be in quotes.