Good to know, I was hoping for a quick fix. I only work in this space about once a year and I know very little about Unison systems which this rack is linked to. The former school principal/director knows the most about the system but that's not a whole lot and he hasn't been around much since retiring.
It's the upper left button, " _v_ " symbol, as attempted n ASCII.
Now that's funny!This is a result of using Rope Light ;-)