UHU Low Power - They Work but how do I

[bill south]

...do an external reset without a serial computer????
Well, I fiinally figured everything out and have my motors spinninng with Mach 3 using the original Smartbaga UHU systems which he built for me a few years ago (yeah, I'm kinda slow). I just need some tuning and then on to the Router for some ass kicking chip removal!!!
But, during bench testing, I have to use the soft reset "R" when I get an error either with Mach or a system overrun error. When I finally get to the finished configuration, I don't want to have a second terminal hooked up to the serial port to take care of any overrun errors. How do you reset the system (soft) when an error occurs when you e-stop, overrun or Mach shuts down for a reset error???? Hope I'm asking this in a clear fashion!
Help, I've searched what seems like a thousand entries in the UHU thread (original) and can't find anyone addressing this scenario??????
Thanks in advance and thanks all for the great information!!!
Bill

[bill south]

Help.
Bill

[H.O]

Hi,
Personally I'm not familiar with that version of the UHU but I looked at a schematic I have for the "original" UHU and there's a jumper, K10, which can be used to reset the drive. Do you have that on yours?

What I did on my HP-UHU, which also has this jumper was to wire an opto-isolator to it so I could trig a reset with an external signal.

[bill south]

Thanks H.O.
Yes my boards do have that open jumper. Does it take a high signal or low signal to reset the board (or would a set of external relay contacts across the jumper do the job)? I'd like to take an output from my CNC4pc bob to all three boards to reset them after mach resets automatically. Any ideas how that would work?
Again, thanks for the info. Seem like with all the hundreds of posts on the uhu thread(s), someone would have a definitive answer! Once I'm complete, I hope to add to the thread(s) a schematic of my system. It appears that one is needed!
Have a good day.
Bill

[H.O]

Hi,
The UHU-chip resets when a logic low signal is applied to pin 1 of the chip. As you can see in the schematic one side of the jumper is connected to pin 1 and the other to GND so shorting those two pins will reset the chip.

The best way to do this "externally" is with a small relay or an opto-isolator, as close to the jumper as possible (one for each drive). Routing long cables away from the PCB is not a good way in this case so keep it as close to the drive as possible.

As I said, my approach was to take a PC817 opto-isolator, wire the emitter (pin3) to the "GND-side" of the jumper and the collector (pin 4) to the "reset-side". The LED of the opto-coupler is then driven by a 24V signal in my case but you could drive it with the output on break-out-board. Remeber to put a resistor in series with the LED on the opto-isolators.

If you prefer to use relays that'll be just fine too, as long as the output of the BOB can supply enough current to energise the relay.

/Henrik.

EDIT: Please note that the numbers in the small schematic attached is not the pin numbers on the PC817 opto-isolators.

[bill south]

Thanks again HO. Where did this schematic come from. It looks like part of a larger system. I'm going to try and source some opto's and do that kind of mod.
Bill

[H.O]

Hi,
It's part my schematic for the Abene conversion that I'm working on.

[bill south]

Thanks again Henrik;
I'm going to give it a shot. Unfortunately, I can't look at your conversion thread because I'm at work and the corporate filters will not let the pictures through. I'll look at it when I get home tonight.
Have a good day.
Bill