(Guide Version: 1.0)
UPDATE 3/18/2019:This guide does not apply for CNC12 Version 4.14 and higher. All of the issues reported here have been fixed in version 4.14. If you are still running Version 4.12 and are having issues with probe setup, I highly recommend to upgrade to the latest version of Acorn CNC12 now. here is link. https://www.centroidcnc.com/centroid_di ... loads.html
and Follow this Probe Setup Guide
UPDATE 9/29/2018: An issue has been found that impacts MDI functionality with removable Touch Probes with Input Type NC. If a TP with Input Type NC is being disconnected, all G=Move commands (e.g G28) executed from the MDI are causing Error 916. It looks like the MDI is always checking the input configured in parameter 11 for a trip signal. When the TP is being removed, that signal will open which is the same status as a trip signal. This issue is currently being investigated and the guide will be updated if a solutions is being found. If somebody has a solution for this, please post it below.
I’m the proud owner of an Acorn Board with CNC12 control software. I think the Acorn Board is a fantastic solution and was very easy to install and configure up to the point when I tried to configure both, a Touch Probe and a Tool Touch-Off Plate on my system. If you have tried that too, you might have encountered that this can be a challenging process because there are some glitches in the CNCWizard and the CNC12 software when using non Centroid probes that will not always give you the expected results. This guide is intended to make probe configuration on Acorn an easy and straightforward process.
Disclaimer: USE THIS GUIDE ON YOUR OWN RISK!
I am not affiliated with Centroid in any way and I do not have access to the source code of CNCWizard and CNC12. My findings are based on extensive testing and reverse engineering to find out the relationship between the Input configurations done in CNCWizard, the parameter settings that the Wizard generates and the behavior of CNC12 with these parameters. My findings are based on CNC12 Version 4.12. Based on my tests, the following guide should get any combination of Touch Probe and Tool Height Setter working with Acorn and CNC12. My tests were focused on verifying that the probing cycles are working with the correct trip signals and if the configuration has any impact on jogging and spindle lock. This guide has not been certified by Centroid and I cannot give any guarantees that all combinations will work 100% for you.
Definitions
Trough out the guide I will use the following abbreviations:
TP = Touch Probe used to set work coordinates etc.
TT = Tool Touch-Off Plate used to set Z-Reference / Tool Height Offsets
NO = Normally Open is used for the type of probes that have an open Input when NOT tripped
NC = Normally Closed is used for the type of probes that have a closed Input when NOT tripped
Fixed = Hardwired probe connection. This also includes probes with a plug that will be left connected permanently
Removable = A probe that will be connected for probing and removed after probing is completed
Input/Output Map in CNC12 (Alt i)
To help with troubleshooting Input/Output problems, the Input/Output Map in CNC12 is a good place to start and can be accessed by pressing Alt i on the main menu of CNC12 and it will look like this:
It is important to understand the meaning of the colors of the LEDs. The Acorn has a total of 8 Inputs that can be seen on the left of the first row of the Map screen. If an Input is configured in the Wizard as NO, the LED for that Input will have a line on top of it (look at Input 7 in the picture as an example). No line above the LED indicates the Input has been specified as NC in the Wizard. This is true even for Inputs that have been configured as “Unused”. By default an “Unused” Input is configured as NC but when you change that to NO, a line above the LED will show up.
So what do the colors mean? There seems to be a misperception that Green means Input is closed and Red means Input is open. That is NOT the case. A LED shows Green when the signal on that Input matches the setting for that Input in the Wizard. So if an Input has been configured as NO and there’s no signal on that Input (Input is Open), the light will show Green and will turn Red when the Input closes. For an Input that has been set to NC, the light will be Green when the Input is closed (Input pulled to Ground) and turn Red when the Input opens.
If you have already configured probes on your system, check the color of the LED of your probe Input. If the color is Red when the probe is NOT tripped, you have configured the opposite Input Type of what your probe really is. The good thing is your probe might still work correctly as long as your parameters do have a matching, inversed Input value. The problem is that the rules for inversion are inconsistent with certain parameters.
So when you follow the Guide, pay close attention if an Input value of a parameter is positive or negative. If you follow the Guide to the T, you should get a Green light for your probe Input LED when the probe is not tripped. The settings might not always make logical sense but they should work.
Warning
IMPORTANT CNCWizard is overwriting the parameters every time you save a configuration file. If you are making manual parameter changes in CNC12 and run the Wizard after making these changes, there is a good chance the Wizard will overwrite your changes again and will leave your probes in a non-working state. So avoid using the Wizard after making manual changes. If you have to use the Wizard again for some reasons, make sure you re-configure these parameters again when you re-start CNC12.
How to use the Guide
Step 1
There are two tables, one for the TP and one for the TT. Start each table in the left column, answer the question in the heading of the column and pick the row that matches your situation. Work your way to the right until you get to the columns that give you the settings for the CNCWizard and CNC12 for your configuration.
I suggest that you download and print out the configuration tables below and mark the recommended settings for the TP and the TT (if you have both) before you go to Step 2. In the “Comments” column there are reference letters and numbers that point to the corresponding Comments below the configuration tables that are relevant to your configuration and will give warnings or additional information why these settings were chosen. When you have determined all the CNCWizard and CNC12 parameter settings for your probes, go to Step2.
Step 2
Start CNCWizard and configure all Inputs with the recommended settings from the Guide. Save the configuration and exit CNCWizard.
Step 3
Start CNC12 and press Alt i to get to the Input/Output Map. Verify that the LEDs of your probes are Green when connected and NOT tripped. The LED should turn Red when tripped. If this is not the case, you have selected the wrong Input Type in CNCWizard for your probe (or something might be wrong with your wiring). Go back to Step 1 and follow the Guide using the opposite Input Type.
If your LEDs work correctly, go to the Parameter Configuration page by selecting Setup [F1] -> Config [F3] -> Parms [F3] from the Main Screen of CNC12 (you might need to press the ESC key until you reach the Main Screen). If you have Password enabled, you will be prompted for a Password. The default Password is 137. Change all the Parameters to the recommended values from the Guide. Save the changed Parameters by pressing Save [F10].
Step 4
Test your configuration and verify that the probing cycles in CNC12 can be started and are recognizing the trip signal. Be aware of the following:
- The availability of probing cycles depends on the version of CNC12 you have (Free, Pro or Digitizing Bundle). Check Centroid’s website for more information what’s available for your version.
- On the Setup [ F1] -> Tool [F2] -> Offset Lib. [F1] screen the “Z-Ref [F1]” function only works if Parameter 43 has been configured to use the TT to set the Z-Reference. For details about Parameter 43 see Step 5.
- On the Setup [ F1] -> Tool [F2] -> Offset Lib. [F1] screen the “Auto Measure [F3] functions does look at different parameters than the “Z-Ref” function. That means that the “Z-Ref” function might work but the “Auto Measure” function doesn’t.
I recommend not mounting the probes onto your machine for the tests. Leave them somewhere safe and create a trip signal with your hands. Make sure your machine is in a safe position before you start a probing cycle so it doesn’t crash into something should a probing cycle not react to the trip signal. Use the RESET-Button to stop a probing cycle that’s ignoring the trip signal from the probe.
Step 5
This Guide focuses on the settings required in CNCWizard and CNC12 to get a probe recognized and force CNC12 to look at the correct Input for a trip signal during a probing cycle. Below is a description of the main parameters related to probing. The values of the parameter numbers in RED should match the values from the Guide Tables. Do not change these values unless you know exactly what you are doing. Check the other parameters if they match your requirements and change them if needed. If you have configured CNC12 to use Inches, the feed parameters are in inches/min and distance parameters in inches. For Metric configuration, feed parameters are in mm/min and distance parameters in mm.
I also recommend checking Centroid’s documentation about more details of these parameters.
- Parameter 11 : Input Number of the TP. If you have only a TT or you have a removable TP and TT that are sharing the same Input, enter the same Input Number into Parameter 11 & 44. Default value is 0.
- Parameter 12 : Tool Number of the TP. This number must reflect the position of your TP in the Tool Library. Default value is 0.
- Parameter 13 : Recovery Distance for TP. This is the distance the TP moves off of a surface after a trip signal has been received before attempting to traverse parallel to the surface. The default value is 0.05” or 1.27mm.
- Parameter 14 : Fast Probing Rate for TP and TT. This speed is used for initial surface detection. The default value is 10ipm, 254mm/min.
- Parameter 15 : Slow Probing Rate for TP and TT. This is the speed used for the final measuring move and is a tradeoff between speed and accuracy. The default setting is 1ipm, 25.4mm/min.
- Parameter 16 : Maximum Probing Distance for TP and TT. This is the maximum distance a probing cycle “searches” for a surface in a given direction if no travel limits have been entered. The default is 10”, 254mm. This might need to be increased if very large features are measured.
- Parameter 17 : Detector Location Return Point for TT. The values of this parameter can be as follows:
- 0 = The tool measurement will take place at the current X and Y position (Default Value)
- 1 = Use X and Y position configured in G28 (same as G30 P1)
- 2 = Use X and Y position configured in G30 (same as G30 P2)
- 3 = Use X and Y position configured in G30 P3
- 4 = Use X and Y position configured in G30 P4
- Parameter 18 : PLC Input Spindle Inhibitor for TP. This parameter should supposedly be configured with the Input Number for the “ProbeDetect” signal of the TP. My findings are that this parameter can be 0 and ProbeDetect still works as long as the Detect Input Signal matches the configured Type NO or NC. If an Input Value is being entered in parameter 18, it always needs to be a positive number, no matter if the Detect Signal is NO or NC. If a negative value is entered, the probing cycle will give a "Probe not detected" error. Default value is 0.
- Parameter 43 : Automatic Tool Measurement Options for TT. This is a binary parameter that allows 3 separate settings been configured in one parameter. This parameter should have been configured correctly by the Wizard based on the information you provided in the “Tool Touch Off Options” pop-up window when you selected “ToolTouchOff” for an Input.
This is how the parameter is configured (just add up the number for every option you need):- The default value is 0
- Add 1 if you want the Height of the TT been subtracted from the measurement. The height of the TT is configured in parameter 71
- Add 2 to use the TT for setting the Z-Reference. The “Z-Ref [F1]” function will not work without this
- Add 4 if you want a Warning Message to attach the TT before probing.
- Parameter 44 : Input Number of the TT. See Comment 5) for additional information
- Parameter 71 : The Height value of the TT. Configure also parameter 43 if you want this height value of the TT be subtracted from the Tool Height Measurement. Default value is 0.
- Parameter 155: Centroid DSP Probe installed. Unless you have a Centroid DSP probe, this value needs to be 0, which is the default value.
- Parameter 257 : Input Number of the Detect Input of the TT. IMPORTANT! This parameter plays a major role in getting a TT working properly. If this parameter is 0, which is the default value, the probing function Setup [ F1] -> Tool [F2] -> Offset Lib. [F1] ->“Auto Measure [F3] will look for a trip signal on the Input configured in parameter 11 instead of parameter 44. If you have a TT without a Detect Input, you need to fake a signal in parameter 257 in order to get the “Auto Measure” function to accept a trip signal from the TT and not the TP. This can be achieved by entering the positive value of the TT Input in this parameter. You will get the right settings if you follow the Guide.
If you reached this point and followed the Guide to the T, you should hopefully have a machine with working TP and TT. If you have a working configuration, create a report.zip file so you can restore your settings in the case the Wizard will overwrite your settings again.
If the provided settings don’t work for your configuration, if you find any mistakes or have suggestions to make the Guide better, please report it in this thread.
Below is more information about the issues I have found using Wizard Settings. This information might help you troubleshooting your configuration settings should the Guide fail you.
CNCWizard Input Settings related to Probing
This list describes all the probe related Input PLC Names available in CNCWizard, what they are supposed to do and my findings:
- ProbeTripped : This is used to configure the Input of the TP. Instructions say to configure the Input Type with the signal your TP has when tripped. So in theory this should be set to NO for a TP that is really NC and to NC if the TP is in fact NO. There might be some history behind it that this has been implemented this way but it’s very confusing and not really necessary. It will also give you inverted LED colors in the Input/Output Map.
Be aware that when you configure an Input as “ProbeTripped” with Input Type NO or NC, CNC12 will prevent Fast Jog to protect your probe if the signal on the probe Input matches the configured Input Type setting from the Wizard. So if you have configured the Input as NC and the Input is closed, or the Input Type is configured NO and the Input is open, you can’t switch to Fast Jog until that signal reverses. This is of course a problem for hard-wired probes, as the signal will always match when the TP is not tripped and will never allow you to Fast Jog your machine anymore. It’s also a problem for removable probes with Input Type NO because CNC12 cannot see a difference between an open signal from a working probe or an open signal from a disconnected probe. To get around this issue, you need to configure your TP Input as “Unused” instead of “ProbeTripped”. See Comment 4) for side effects.
- ProbeDetect : This is used to configure the Input of the Acorn that has the Detect Signal of the TP wired to it. The Input Type can be configured as NO or NC and CNC12 will prevent the spindle from spinning when the signal on this Input matches the Input Type. This Input can be shared with a TT if your TT doesn’t require your spindle to spin. Note that the Wizard currently has no PLC Name for a TT Detect Signal. If you need a second Detect Input for your TT or if you need a Detect Input that lets your spindle spin, configure the Input as “Unused” with the correct Input Type NO or NC as required.
- ToolTouchOff : This is used configure the Input of the TT. As soon as you select this PLC Name for an Input, the Wizard will pop-up a “Tool Touch-Off Options” window where you can specify several options for the TT. These options will configure the following parameters:
- 14 : Fast Probing Rate (value shared with TP, inches/min or mm/min depending on your machine settings)
- 15 : Slow Probing Rate (value shared with TP, inches/min or mm/min depending on your machine settings)
- 16 : Max Probing Distance (value shared with TP, inches or mm depending on your machine settings)
- 43 : Automatic Tool Measurement Options (see Parameter Table above what the number means)
- 71 : Height of Tool Touch-Off , inches or mm depending on your machine settings)
- Unused : Configure an Input as Unused if you want to get around the restrictions of a specific PLC Name as described above
Other Considerations
Safeguard your Probe with a Detect Input
If you are using removable probes, I highly recommend using a Detect Input. If both of your probes, TP and TT are the same Input Type, you can share the Probe Input as well as the Detect Input between the probes. Just follow the Guide using the same Probe and Detect Input for both probes.
Usually the Plug and Connector of a probe have a lot of unused pins. On the connector side just wire one spare pin to a Detect Input and a second spare pin to COM on the Acorn board. On the Plug side of the probe, just shorten the matching two pins and your probe has a Detect function with Input Type NC.
For hard-wired TPs there is no good automated way to prevent your spindle from spinning. You should make it a habit to lock the spindle (or turn off power to the spindle if there’s an option) when you mount the TP and unlock when you remove it. If you have no spindle lock or power switch, you can consider installing an On/Off Spindle Lock switch on your control box that you wire as a “ProbeDetect" Input on your Acorn board. You could also use one of the AUX keys for this function.
Saving Inputs
If you are short on Inputs and both of your probes, TP and TT, have the same Input Type, you can consider using the same Input for both probes.
If both probes are hard-wired and the same Input Type, you can wire them to the same Input as follows:
- Input Type NO: Wire them parallel to the same Input
- Input Type NC: Wire them in series to the same Input
If both TP and TT are removable and have the same Input Type, you can use the same Input for both probes (see also “Safeguard your Probe with a Detect Signal” above).
If you use any of these options, follow the Guide by using the same Input Number for both probes and you should get working settings for this type of configuration.
Please post below your probe details if the guide did or didn't work for you.
-swissi
