KVM Daisy Chain Setup - How to control more than one slave KVM

I have 3 TESmart KVM switches. A master KVM and 2 slave KVM's. The master KVM is controlling which slave KVM I'm connecting to and this master has a keyboard, mouse, and HD monitor. But I have a macro controller that I want to use to control the channels on ALL slave KVM's. The macro controller has scripts that were programmed to simulate the key combination needed to change the slave KVM's channels and when connecting this macro controller directly to a single slave KVM and pressing a button changes channels just fine. To be more specific, I want to switch to channel 3 on the 2nd slave. I use

Question by Saun on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.