Sage:
The empty buffer mean M4 isnt calling Darwin to trigger a change in its IO.. Thats good. It means all is normal there..
Im thinking... In Mach3, the port gets initialized and all pins are set to low, even if unused. Darwin isnt doing that,
if a pin is not specifically listed as used, it is left alone. So..when after loading the port is reset, the pins go to whatever default state they
wish to be at. It may be that is toggling things when the charge pump comes on. The charge pump starts when the program does and the port
gets reset at the same time. So Im wondering if this is simply a case of the pin is getting toggled to a low as a static reset state and triggering
the relay. Darwin doesnt care or touch any pin reported as unused, so it will be high or low depending on the type of printer port and its designers
reset state. Normally I think this is the pin getting pulled high.. So if you then enable a signal on that pin and dont use it, the pin will get pulled
to whatever inactive state is called for ( depends on the "negate" setting ). Could this be what your seeing?
Art