the MLT circuit is derived from the dual timer board. there are two potentiometers on the dual timer board, one for the TA relay for transferring to delta in a wye-delta system, and one for the MLT timer. both timers are activated by the normally open UA contact feeding the board. when the timer for MLT expires, the board outputs a ground signal to the appropriate input board terminal. there is also a low oil switch that can be added that when closes sends a ground signal to the same input board terminal as the timer does. I am not sure, but there may have been some early omega 1000 that had a MLT that was generated by software. If you have an input called MLT, then it is not software generated.

Thanks for the quick response. So once the board times and goes on MLT it should maintain a low signal on that MLT input until the power is cycled right? I do see on the print where the low oil switch is connected to the "z" pin on the dual timer board. This suggests that the MLT input does not need to be constant to force an MLT, it could MLT just from the low oil switch closing for a second. Does this sound right that the MLT input is self-sustaining if grounded momentarily?

when the timer expires, it sends a ground signal to the input momentarily, then the timer resets because UA relay drops out and resets the timer. you wont know what caused the mlt, the switch or the timer.