step 50b triggering off the negative terminal/points

[thedude]

hello everybody. i dont know how to make a decision if i am going to trigger off of the coil negative. planing going ford edis-4 with VR sensor 36-1 trigger wheel into a 1974 2002 bmw the instructions say to do one or the other 50a or 50b but not both?

[DaveEFI]

EDIS produces a tach signal from its controller. Called PIP. Refer to the EDIS sections in the manual. But if you are still at the planning stage, consider adding high current coil drivers to MS and have it do the wasted spark.