Is there a simply (easy?) way to get Mach3 to generate a PWM pulse signal even when the spindle OFF?

On my setup, I have a brushless spindle powered by an ESC.

The problem in need of a solution is the ESC is expecting a pulse even for the OFF speed.

I am able to generate a PWM signal for when the spindle is on, but this is perplexing me.

Ideas?