There's 2 ways you can do the bob. Common anode or Common cathode.
Common anode is when all driver positives are connected to vcc/pc5v+ and negatives are connected to control pins. (low).
Common cathode is when all driver negatives are connected to ground and all driver positives are connected to control pins. (high).
So common anode (for example 4 axis cnc)
ALL DRIVERS> pul+/dir+/Enble+ are connected to 5v+.
P1 is pwm, jumper select for pin or analog output.
P2X, pul-
P3X, dir-
P4Y, pul-
P5Y, dir-
P6Z, pul-
P7Z, dir-
P8A, pul-
P9A, dir-
P14, enbl- ON ALL DRIVERS
P16, aux (coolant)
P17, M3/M4 jumper select pin or relay
For common cathode simply switch all the +/- wiring around, some drivers prefer high pulsing. Change active low to high.
Eg, X= pul-/dir-/enbl- to GND. Pul+ to P2 dir+ to P3 (high).
And so on.
Mach3 for on board relay and analog use.
Axis as above for P2-9, pin? Port1
Spindle, step= P1, Dir= 0!!!. Active Low.
If you put dir pin to 17 the relay goes active on boot up.
If use spindle relays is checked and pin set in dir the relay does dumb stuff.
Outputs.
Enable#1, P14 port1
Out#1= Eg M7 mist, P16 port1. Low
Out#2= M4, fake ccw/cw output call it, P17 port2. Low
Out#3= M3, connected ccw/cw output, P17 port1. Low
Having m3 and m4 helps not confuse the single relay.
Spindle. M3, output#3. M4, output#2. M7, output#1.
Enable relays, enable pwm.
Should be more or less.
Here is a pdf manual. Wiring is done as common anode.
https://warp9td.com/images/BOB_Vendors/StepperOnline/ST-V2.pdf