ATC Toolchanger logic

[sweep]

Hi All,

I have a late 80's Triac with 6 station BT35 ATC controlled by NEE SMCU; actually the serial number of the ATC is 001!
As part of my very long modification to Mach3 I want to still keep the ATC.
After a lot of time with the oscilloscope I captured and recorded the code that is sent from the Triac's motherboard to the ATC unit on the rear of the machine. That, in fact, was some time ago as I have since stripped out the old motherboard and scrapped it.
What I can do is send strings of code from my PC directly to the ATC controller via the serial port and control all the functions that were originally controlled by the Triac motherboard: these include finding datum, identifying tool already in spindle when datuming, and the full toolchanging procedure for any of the 6 stations. I have also figured out the original relay feedback logic for 'ATC busy' and 'ATC fault'
Eventually i'll write this into a macro in Mach3, but for the moment i'm just sending the code from Hyperterminal.
What I don't understand, and here come the questions, is what controls the instant when the spindle stops?
The way I see it (I video'ed it!) the spindle idles at around 50rpm for a few moments then as the tool change is initiated stops with its drive dog roughly facing the carousel. Exact alignment is then accomplished by shaped ped on the spindle release plunger.
Looking at my video it seems the spindle stops pretty much instantly but the Lenze DC motor isn't set up for dynamic braking, and the only guide to where the drive dogs are seems to be the pulses on the spindle speed proximity switch. So, the only 'logic' I can see is that the original motherboard counted pulses and then switched off the spindle at a predetermined period after the last pulse, calculated (trail & error?) by the inertia of the spindle and toolholder.
Can anyone cast any light on the actual design logic of the Traic motherboard/NEE ATC or do you nice people in Brighouse have any old documents etc. I do have the SMCU programming guide but that doesn't help

...Sweep

[Denford Admin]

I've just added a recently scanned bit of info here:
viewtopic.php?f=47&t=3062

[sweep]

Thanks for the uploaded info.
Some of it must already on the site hidden in other documents as I seem to have quite a few of the pages.
Unfortunately it doesn't seem to answer my question about the logic.
Page 27 of the upload shows a cable with three wires; Common (red), Ready (yellow), and error (green). This cable is connected into the SMCU panel and is just connected to two relays (I think). In fact, it might be a good idea if someone would confirm that the 'error' connection is for relay or data stream.
When the ATC is idle and ready for an instruction, i.e. finished its last cycle, the 'ready' relay closes which is fair enough.
What I can't do though is get any fault to open the 'error' relay, unless this wire carries a logic stream? For example, i've deliberatley disconnected air from the ATC and positioned the carousel mid stroke and then issued the datum command but it just sits there.
I could ignore this connection and just send the next instruction when the 'ready' relay closes, but i just fancy having an error light on my panel!

...Sweep