Ignitions with hall sensors will trigger at 1 rpm when the magnet passes the edge of the sensor...
C&H ignitions will fire when the switch is turned on and off..
DA and older 3W ignitions don't use a hall sensor and need some rpm to trigger the circuit..
New 3W ignitions use two hall sensors and will trigger at 1 rpm..
Some Falkon ignitions use a hall sensor, trigger at 1 rpm.
If you rotate the crank and get no spark but switch it on an off and get spark, the sensor is bad, usually caused by lack of a ground...
Be sure you have the spark plug in the cap and touching the engine when testing, some hall sensors blow right away and some take a while...