I guess I never posted the schematic to the circuits that I made to control the servo with Open Collector vs Line Driver Interface. Agreed with Hood, Line Driver is better, but if your using PP like I did, Open Collector will work just fine. Your limited to 200Khz, but you can’t even get close to that with Mach3 and your PP
To convert 5 Volt TTL to Open Collector, you can use your basic NPN transistors or 74LS05 IC. See the attached circuit diagram, this is what I have used on both the BP412 and the DM4800 to Servo Interface. I’ll have to dig into the Servo Book to see my notes on all the connections used, but at least this shows STEP, DIR, EN and eStop back from the Servo Interface.
JH