Stepper motor Pulse Signal Generator module

Hi there


I've got generator module and stepper driver connected with two power source 24v(driver) and 5v(generator) like in the picture



I use PUL-, DIR-, and ENB-, 3 cables connected to the M542 driver
In this setup I should join all pluses together and connect to common anode(+)

I do not why but everything works without this cable - common anode(+).
I am confuse here. I send only positive signals to the module
I can change direction of the motor (DIR) and switch on/off the motor (ENA)

Not the same situation if I use only PUL+ DIR+ ENB + without common cathode this time(-).
Without common cathode I can only run one direction (like having only PUL+ and (-)cathode or PUL- and (+)anode two cables connected)
I can have on/off function (ENA, because module send HI signal and disable(off) the driver.

I know that signal I get is PWM square wave, multimeter allows to check polarity of such a signal (all + or -)
Can anyone explain how this works please, many should benefit too.

System got all function start/stops using ENA and Direction using DIR all done by 3 cable connected to (-) without having common anode(+)


Cheers
Tom