Probing, limit switches and more newbie questions...

All things related to Centroid Oak, Allin1DC, MPU11 and Legacy products

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JasonPORC
Posts: 26
Joined: Wed Jan 27, 2021 11:30 am
Acorn CNC Controller: No
Allin1DC CNC Controller: No
Oak CNC controller: Yes
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CNC12: Yes
CNC11: No
CPU10 or CPU7: No
CNC Control System Serial Number: none

Probing, limit switches and more newbie questions...

Post by JasonPORC »

Good day all.

Got my oak yesterday and I’m about to start a build series, but had a few more questions about general practices.

1. Where do I purchase Swiss’s Probing App? For the life of me, I can’t seem to find that info. It’s probably right in front me.

2. I don’t mean to oversimplify this, but I’m trying to learn. Why can’t I just plug in a 2 wire probe/TT into an extra Oak input? It’s just a switch correct? Is this possible? I’m sure there is a good reason there’s a probe input on the board, but I’m wondering if this would work. (Again, trying to learn here. Please be kind. Ha ha) I already own a two wire probe and TT, and would like to reuse them on the build, but I’ve read enough other posts here about probe (nc/no contacts) and might consider just purchasing the Centroid Probe and TT just to simplify. Thoughts?

3. What is the logic behind having both high and low inputs for limit switches, vs. just using 2 switches in series into one input? (As I believe the acorn board is?). I plan on wiring up all 8 limit switches as recommended here in the forum, And plugging them into inputs 1-8, but I’m curious why it’s beneficial to use 2 inputs onto the PLC vs. just one that has 2 actual limit switches on it. (Again, just trying to learn. Not being critical or cheap. I just like understanding as much as I can)

Thanks in advance for any insider info someone’s willing to share. Cheers!
cncsnw
Posts: 1971
Joined: Wed Mar 24, 2010 5:48 pm

Re: Probing, limit switches and more newbie questions...

Post by cncsnw »

If I recall correctly, in the original MPU11 architecture, the on-board inputs (e.g. INP769-INP772 on the Probe header) responded faster than those that came in from a PLC board, and therefore provided better repeatability for probing. I do not know if that is still the case with Oak and Allin1DC, where the first 16 PLC inputs are on the same circuit board.

It is not hard to connect whatever probe and/or tool detector you want to the provided probe input. It is just a Molex Mini-Fit Jr. plug (if you want to plug directly into the Oak) or an Amphenol CPC plug (if you want to use Centroid's pigtail out to a bulkhead connector).


With separate minus and plus limit switch inputs, the control can allow you to move back off of a tripped limit switch.

If you wire both plus and minus limits to a single input, the control has to prevent movement in both directions, so then you need to provide a limit defeat function, or use manual handwheels to get back clear of a tripped limit switch.
JasonPORC
Posts: 26
Joined: Wed Jan 27, 2021 11:30 am
Acorn CNC Controller: No
Allin1DC CNC Controller: No
Oak CNC controller: Yes
MPU11 & GPIO4D -w/ 3rd Party Drives: No
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No
CNC Control System Serial Number: none

Re: Probing, limit switches and more newbie questions...

Post by JasonPORC »

AHHHH! That all makes since. Thank you! As per usual, this stuff has long been figured out.

How about buying the probing app? Any ideas there?
swissi
Posts: 471
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CNC11: No
CPU10 or CPU7: No
CNC Control System Serial Number: 985DADEB24D5-0309180716

Re: Probing, limit switches and more newbie questions...

Post by swissi »

JasonPORC wrote: Wed Apr 07, 2021 12:09 pm Good day all.

Got my oak yesterday and I’m about to start a build series, but had a few more questions about general practices.

1. Where do I purchase Swiss’s Probing App? For the life of me, I can’t seem to find that info. It’s probably right in front me.

2. I don’t mean to oversimplify this, but I’m trying to learn. Why can’t I just plug in a 2 wire probe/TT into an extra Oak input? It’s just a switch correct? Is this possible? I’m sure there is a good reason there’s a probe input on the board, but I’m wondering if this would work. (Again, trying to learn here. Please be kind. Ha ha) I already own a two wire probe and TT, and would like to reuse them on the build, but I’ve read enough other posts here about probe (nc/no contacts) and might consider just purchasing the Centroid Probe and TT just to simplify. Thoughts?

3. What is the logic behind having both high and low inputs for limit switches, vs. just using 2 switches in series into one input? (As I believe the acorn board is?). I plan on wiring up all 8 limit switches as recommended here in the forum, And plugging them into inputs 1-8, but I’m curious why it’s beneficial to use 2 inputs onto the PLC vs. just one that has 2 actual limit switches on it. (Again, just trying to learn. Not being critical or cheap. I just like understanding as much as I can)

Thanks in advance for any insider info someone’s willing to share. Cheers!
The ProbeApp is Donation-Ware and is is available to all supporters who made a donation in any amount they think is reasonable. All donations will be used to cover some of the costs of the test infrastructure I need to develop and test the app and future version. Just send me an email at swissi2000@gmail.com and I'll send you the information how to make a donation.

Regarding the probing input, the servo version of CNC12 for OAK and AllIn1DC does not yet have the much more universal support for probing devices that the Acorn version has.If you don't want to jump hurdles, only get a Touch Probe (TP) and/or Tool Touch Off Plate (TT) of type Normally Open (NO). Everything else will give you a headache to connect.

Also while the TP and TT can have their own Detect Input (771 for TP and 772 for TT), they both share the same Trigger Input 769 and I might be wrong on this but my hunch is that this input is hard coded in CNC12 so I don't think you can use any other trigger input than 769.

-swissi
If you are using Fusion 360, check out my CNC12 specific Post Processor
If you are using a Touch Probe, Tool Touch Off Device or a Triple Corner Finder Plate, check out my ProbeApp

Contact me at swissi2000@gmail.com
martyscncgarage
Posts: 7883
Joined: Tue Mar 28, 2017 12:01 pm
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DC3IOB: No
CNC12: Yes
CNC11: Yes
CPU10 or CPU7: Yes
CNC Control System Serial Number: none
Location: Mesa, AZ

Re: Probing, limit switches and more newbie questions...

Post by martyscncgarage »

Spend the money and buy the probe header cable, its about $55, prewired. Part number 11085. Plugs right into the PROBE connector on Oak.
You can by the mating Circular Pin Connector (CPC) and put it on your probe. That way you have a Centroid standard Probe connector.
Its the right way to do it in my opinion....
Marty
Reminder, for support please follow this post: viewtopic.php?f=20&t=383
We can't "SEE" what you see...
Mesa, AZ
martyscncgarage
Posts: 7883
Joined: Tue Mar 28, 2017 12:01 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: Yes
Oak CNC controller: No
MPU11 & GPIO4D -w/ 3rd Party Drives: No
DC3IOB: No
CNC12: Yes
CNC11: Yes
CPU10 or CPU7: Yes
CNC Control System Serial Number: none
Location: Mesa, AZ

Re: Probing, limit switches and more newbie questions...

Post by martyscncgarage »

Info on Swissi's probe App: viewtopic.php?f=60&t=4973

Make sure you wire and bench test everything. Its far easier to work on the bench than inside a controller cabinet
Follow the Oak Schematic as well including the TB-1 Terminal Block layout.
Just some advice....
Marty
Reminder, for support please follow this post: viewtopic.php?f=20&t=383
We can't "SEE" what you see...
Mesa, AZ
JasonPORC
Posts: 26
Joined: Wed Jan 27, 2021 11:30 am
Acorn CNC Controller: No
Allin1DC CNC Controller: No
Oak CNC controller: Yes
MPU11 & GPIO4D -w/ 3rd Party Drives: No
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No
CNC Control System Serial Number: none

Re: Probing, limit switches and more newbie questions...

Post by JasonPORC »

Thank you Gents!

I’ll shoot an email over to swissi later.

This is all such great info, and I’m slowly learning some of the actual coding and hardware differences between acorn and the servo unit architecture.

In an attempt at continuing my education, My next question is this: what’s the difference between a detect and a trigger input? I’m guessing it’s something like the probe touches the part, that wakes up the probe and then a few milliseconds later it triggers? Maybe? Ha ha. I don’t know. As mentioned earlier, I just thought it was a dumb switch that is on or off. I know all the high end probes have multiple connections and I’ve never really understood why. Again, just trying to learn. I’m sure there is solid logic and engineering here.

And Marty. I doubt this damn board is gunna leave my bench for a few months. I’ve watched your videos. I know better. Ha!

Thanks again for the education and support! Cheers
martyscncgarage
Posts: 7883
Joined: Tue Mar 28, 2017 12:01 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: Yes
Oak CNC controller: No
MPU11 & GPIO4D -w/ 3rd Party Drives: No
DC3IOB: No
CNC12: Yes
CNC11: Yes
CPU10 or CPU7: Yes
CNC Control System Serial Number: none
Location: Mesa, AZ

Re: Probing, limit switches and more newbie questions...

Post by martyscncgarage »

JasonPORC wrote: Thu Apr 08, 2021 11:30 am Thank you Gents!

I’ll shoot an email over to swissi later.

This is all such great info, and I’m slowly learning some of the actual coding and hardware differences between acorn and the servo unit architecture.

In an attempt at continuing my education, My next question is this: what’s the difference between a detect and a trigger input? I’m guessing it’s something like the probe touches the part, that wakes up the probe and then a few milliseconds later it triggers? Maybe? Ha ha. I don’t know. As mentioned earlier, I just thought it was a dumb switch that is on or off. I know all the high end probes have multiple connections and I’ve never really understood why. Again, just trying to learn. I’m sure there is solid logic and engineering here.

And Marty. I doubt this damn board is gunna leave my bench for a few months. I’ve watched your videos. I know better. Ha!

Thanks again for the education and support! Cheers
Take your time, one step at a time. FOLLOW the Oak installation manual and you should be OK. We are here for suggestions if you get stuck.
What drives are you going to use?
Reminder, for support please follow this post: viewtopic.php?f=20&t=383
We can't "SEE" what you see...
Mesa, AZ
swissi
Posts: 471
Joined: Wed Aug 29, 2018 11:15 am
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
MPU11 & GPIO4D -w/ 3rd Party Drives: No
DC3IOB: No
CNC11: No
CPU10 or CPU7: No
CNC Control System Serial Number: 985DADEB24D5-0309180716

Re: Probing, limit switches and more newbie questions...

Post by swissi »

JasonPORC wrote: Thu Apr 08, 2021 11:30 am Thank you Gents!

I’ll shoot an email over to swissi later.

This is all such great info, and I’m slowly learning some of the actual coding and hardware differences between acorn and the servo unit architecture.

In an attempt at continuing my education, My next question is this: what’s the difference between a detect and a trigger input? I’m guessing it’s something like the probe touches the part, that wakes up the probe and then a few milliseconds later it triggers? Maybe? Ha ha. I don’t know. As mentioned earlier, I just thought it was a dumb switch that is on or off. I know all the high end probes have multiple connections and I’ve never really understood why. Again, just trying to learn. I’m sure there is solid logic and engineering here.

And Marty. I doubt this damn board is gunna leave my bench for a few months. I’ve watched your videos. I know better. Ha!

Thanks again for the education and support! Cheers
The trigger or trip signal indicates when the touch probe has hit a surface or a tool has touched the tool touch off plate. CNC12 will record the position at which this trigger signal occurred.

The Detect Signal does tell CNC12 that a probing device has been attached and will activate the probe protection features like the spindle inhibitor. If you have a touch probe in the spindle with a cord attached, you don't want the spindle to turn on accidentally and that's why the detect signal for a touch probe is recommended.

A detect input for a tool touch off device is not really needed, especially if you hardwire the device.

As far as I know, the connection cable that Marty mentioned allows only one probing device to be connected at one time which is a major shortcoming in my opinion as many users want to use both devices at the same time especially if the touch probe is the reference tool and needs to be touch off on the TT to set the reference height.

To work around this, people are using that probe connection cable for the touch probe and then just splice the TT connection into that wire harness to use the same pin on the connector (Trigger Input 769) for the TP and TT and also share the COM pin for both devices. That way the TT is wired permanently and the TP is still removable with Probe Protection features intact and both devices can be used at the same time.

Of course this only works if both the TP and TT are of type Normally Open (NO) so don't make the mistake to get any probing device that's Normally Closed (NC).

-swissi
Last edited by swissi on Thu Apr 08, 2021 2:20 pm, edited 1 time in total.
If you are using Fusion 360, check out my CNC12 specific Post Processor
If you are using a Touch Probe, Tool Touch Off Device or a Triple Corner Finder Plate, check out my ProbeApp

Contact me at swissi2000@gmail.com
martyscncgarage
Posts: 7883
Joined: Tue Mar 28, 2017 12:01 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: Yes
Oak CNC controller: No
MPU11 & GPIO4D -w/ 3rd Party Drives: No
DC3IOB: No
CNC12: Yes
CNC11: Yes
CPU10 or CPU7: Yes
CNC Control System Serial Number: none
Location: Mesa, AZ

Re: Probing, limit switches and more newbie questions...

Post by martyscncgarage »

If you want two devices at the same time, then buy two cables and parallel them together. Cut the molex off one of the cables.
Of course you can make your own if you have the crimp tools and skills to make them.

The control does need the Detect for each device wired. That is usually done on the TT or Probe end.
Unsure why Centroid never made a bulkhead cable with two CPC connectors wired in parallel for those that wanted to leave the Tool Touch off left wired on the table.

Marty
Reminder, for support please follow this post: viewtopic.php?f=20&t=383
We can't "SEE" what you see...
Mesa, AZ
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