A TSU1000 may be able to send a command multiple times in a row from a macro with little enough delay to look like a long duration command to the IR receiver. But a newer Pronto can't.

If you ask for no delay, you still get too much delay. If you ask for some delay, you get even more.

Some newer Prontos let you specify a duration for a signal used in a macro. First you should find out whether duration is the issue.

1) Define a button in which the ONLY item in its action list is the discrete signal you want to test. (I know a discrete is pretty useless as the only action on a button, but it is usefult to TEST it that way).

2) Try a very long press of that button. If it is programmed correctly, the signal will be sent as long as you press the button.

3) If that doesn't work, your model really doesn't understand that discrete code.

4) If it does work, but the same signal in a macro doesn't work (quite common) then you can start experimenting with solutions for that duration problem.

You also can experiment with manual timing on that test button to see how much duration you need.

For some signals, on some models of remote, the solution to a duration problem is send the signal multiple times. Panasonic is a protocol in which that tends to work, but Pronto NG's add so much delay, that with a Pronto NG, that almost never works.