Mach3 and Stepcraft Tool Changer HF

I am trying to get the Stepcraft Tool Changer HF to work in Mach3. In Ports and Pins I have assigned Output#2 to pin 14 of port 1 (same as in UCCNC where it is working). For testing purpose, I have assigned Flood M8 to 2. In the diagnostics window, when I toggle the Flood I see the Output 2 LED light up, but the Tool Changer is not responding. What am I doing wrong?