Retrofit cnc 3axis

Just like the voltmeter, ground to the bottom leg and the probe to the top leg of the transistor.
If will take a bit of getting used to setting the trigger right on the oszilloscope to get a stable trace on the screen.

Be careful with how you connect the oscilloscope though: if it's a mains powered 'scope (and not a handheld battery powered one) the "negative" probe lead is connected to protective earth through the oscilloscope, so if you connect this lead to any other potential than ground, you will short something out. It's not like a DVM where you can hook it up just any way you want.

My oscilloscope. It appears to have the Dc power supply, and two cables. So black on fixed GRN and red i probe my pins. I’ll try to use it tonight.

thanks guys

Hi guys, I apologize for the absence, between work, little fun and some complications, the fight with the penguin took a long time.

After doing the tests I was able to block the
old bmp control xD, so with the pins I had marked, with the help of mr Aciera, I went straight to war with the penguin.

In this second part of the battle I had help from a dear friend via email, general mr D, who guided me and provided a light in the dark streets.
He laid out war trails for me and explained how to use my tin cannon and so much more. Through 817 pc tanks, resistors, op-amps and whatnot we went into battle.
From the idc20 and idc40 breakouts that we had identified together correctly, the connections are equal.
For step and dir we used a ready optoisolator card, and connected to the parallel in OUTput.
For the INputs of the limit switches, the same board mounted in a specular way, always connected to the parallel.
For the tool change and all sensor signals, we used a PCB including Arduino.
Some problems arose due to the GND of idc20 and idc40 which separated on the IO board of the drives but then with the experience of mr D. we managed to solve them.
Now it lacks to complete the software part but I'm finally starting to use linuxcnc.
In the meantime, I really wanted to thank you for the support and help received, in particular to Mr Acieras and Mr D who I will never stop thanking.
Happy new year to all guys!!
I will upload photos soon.

Nice, glad to hear you got it sorted out. Thanks for reporting back!