Mesa Configuration Wizard

This allows you to select a previously saved configuration or create a new one. If you pick Modify a configuration and then press Next a file selection box will show. PnCconf preselects your last saved file. Choose the config you wish to edit. If you made any changes to the main HAL or INI files PnCconf will overwrite those files and those changes will be lost. Some files will not be over written and PnCconf places a note in those files. It also allows you to select desktop shortcut / launcher options. A desktop shortcut will place a folder icon on the desktop that points to your new configuration files. Otherwise you would have to look in your home folder under linuxcnc/configs.

A Desktop launcher will add an icon to the desktop for starting your config directly. You can also launch it from the main menu by using the Configuration Selector LinuxCNC found in CNC menu and selecting your config name.

Testing the latency is very important and a key thing to check early. Luckily by using the Mesa card to do the work that requires the fastest response time (encoder counting and PWM generation) we can endure a lot more latency then if we used the parallel port for these things. The standard test in LinuxCNC is checking the BASE period latency (even though we are not using a base period). If you press the test base period jitter button, this launches the latency test window ( you can also load this directly from the applications/cnc panel ). The test mentions to run it for a few minutes but the longer the better. Consider 15 minutes a bare minimum and overnight even better. At this time use the computer to load things, use the net, use USB etc we want to know the worst case latency and to find out if any particular activity hurts our latency. We need to look at base period jitter. Anything under 20000 is excellent - you could even do fast software stepping with the machine 20000 - 50000 is still good for software stepping and fine for us. 50000 - 100000 is really not that great but could still be used with hardware cards doing the fast response stuff. So anything under 100000 is usable to us. If the latency is disappointing or you get a bad hiccup periodically you may still be able to improve it.

Now we are happy with the latency and must pick a servo period. In most cases a servo period of 1000000 ns is fine (that gives a 1 kHz servo calculation rate - 1000 calculations a second). If you are building a closed loop servo system that controls torque (current) rather then velocity (voltage) a faster rate would be better - something like 200000 (5 kHz calculation rate). The problem with lowering the servo rate is that it leaves less time available for the computer to do other things besides LinuxCNC’s calculations. Typically the display (GUI) becomes less responsive. You must decide on a balance. Keep in mind that if you tune your closed loop servo system then change the servo period you probably will need to tune them again.

This page allows you to select external controls such as for jogging or overrides.

If you select a Joystick for jogging, You will need it always connected for LinuxCNC to load. To use the analog sticks for useful jogging you probably need to add some custom HAL code. MPG jogging requires a pulse generator connected to a MESA encoder counter. Override controls can either use a pulse generator (MPG) or switches (such as a rotary dial). External buttons might be used with a switch based OEM joystick.

joystick jogging uses HALUI and hal_input components.

MPG’s are often found on commercial grade machines. They output quadrature pulses that can be counted with a MESA encoder counter. PnCconf allows for an MPG per axis or one MPG shared with all axis. It allows for selection of jog speeds using switches or a single speed.

The selectable increments option uses the mux16 component. This component has options such as debounce and gray code to help filter the raw switch input.

Here you can set defaults for the display screens, add virtual control panels (VCP), and set some LinuxCNC options..

AXIS defaults are options specific to AXIS. If you choose size, position or force maximize options then PnCconf will ask if it is alright to overwrite a preference file (.axisrc). Unless you have manually added commands to this file it is fine to allow it. Position and force max can be used to move AXIS to a second monitor if the system is capable.

Touchy defaults are options specific to Touchy. Most of Touchy’s options can be changed while Touchy is running using the preference page. Touchy uses GTK to draw its screen, and GTK supports themes. Themes controls the basic look and feel of a program. You can download themes from the net or edit them yourself. There are a list of the current themes on the computer that you can pick from. To help some of the text to stand out PnCconf allows you to override the Themes’s defaults. The position and force max options can be used to move Touchy to a second monitor if the system is capable.

QtPlasmaC options are specific to QtPlasmac, any common options that are not required will be disabled. If QtPlasmac is selected then the following screen will be a user button setup screen that is specific to QtPlasmaC and VCP options will not be available.

HAL pins are created for the user to connect to inside their custom HAL file. There is a sample spindle display panel for the user to use as-is or build on. You may select a blank file that you can later add your controls widgets to or select a spindle display sample that will display spindle speed and indicate if the spindle is at requested speed.

PnCconf will connect the proper spindle display HAL pins for you. If you are using AXIS then the panel will be integrated on the right side. If not using AXIS then the panel will be separate stand-alone from the front-end screen.

You can use the geometry options to size and move the panel, for instance to move it to a second screen if the system is capable. If you press the Display sample panel button the size and placement options will be honored.

It uses a graphical editor to build its XML files. HAL pins are created for the user to connect to, inside of their custom HAL file.

GladeVCP also allows much more sophisticated (and complicated) programming interaction, which PnCconf currently doesn’t leverage (see GladeVCP in the manual).

PnCconf has sample panels for the user to use as-is or build on. With GladeVCP PnCconf will allow you to select different options on your sample display.

Under sample options select which ones you would like. The zero buttons use HALUI commands which you could edit later in the HALUI section.

Auto Z touch-off also requires the classic ladder touch-off program and a probe input selected. It requires a conductive touch-off plate and a grounded conductive tool. For an idea on how it works see:

https://wiki.linuxcnc.org/cgi-bin/wiki.pl?ClassicLadderExamples#Single_button_probe_touchoff

Under Display Options, size, position, and force max can be used on a stand-alone panel for such things as placing the screen on a second monitor if the system is capable.

You can select a GTK theme which sets the basic look and feel of the panel. You Usually want this to match the front-end screen. These options will be used if you press the Display sample button. With GladeVCP depending on the front-end screen, you can select where the panel will display.

You can force it to be stand-alone or with AXIS it can be in the center or on the right side, with Touchy it can be in the center.

The Mesa configuration pages allow one to utilize different firmwares. On the basic page you selected a Mesa card here you pick the available firmware and select what and how many components are available.

Parport address is used only with Mesa parport card, the 7i43. An on board parallel port usually uses 0x278 or 0x378 though you should be able to find the address from the BIOS page. The 7i43 requires the parallel port to use the EPP mode, again set in the BIOS page. If using a PCI parallel port the address can be searched for by using the search button on the basic page.

PDM PWM and 3PWM base frequency sets the balance between ripple and linearity. If using Mesa daughter boards the docs for the board should give recommendations.

Choosing less then the maximum number of components allows one to gain more GPIO pins. If using daughter boards keep in mind you must not deselect pins that the card uses. For instance some firmware supports two 7i33 cards, If you only have one you may deselect enough components to utilize the connector that supported the second 7i33. Components are deselected numerically by the highest number first then down with out skipping a number. If by doing this the components are not where you want them then you must use a different firmware. The firmware dictates where, what and the max amounts of the components. Custom firmware is possible, ask nicely when contacting the LinuxCNC developers and Mesa. Using custom firmware in PnCconf requires special procedures and is not always possible - though I try to make PnCconf as flexible as possible.

After choosing all these options press the Accept Component Changes button and PnCconf will update the I/O setup pages. Only I/O tabs will be shown for available connectors, depending on the Mesa board.

The tabs are used to configure the input and output pins of the Mesa boards. PnCconf allows one to create custom signal names for use in custom HAL files.

On this tab with this firmware the components are setup for a 7i33 daughter board, usually used with closed loop servos. Note the component numbers of the encoder counters and PWM drivers are not in numerical order. This follows the daughter board requirements.

On this tab all the pins are GPIO. Note the 3 digit numbers - they will match the HAL pin number. GPIO pins can be selected as input or output and can be inverted.

On this tab there are a mix of step generators and GPIO. Step generators output and direction pins can be inverted. Note that inverting a Step Gen-A pin (the step output pin) changes the step timing. It should match what your controller expects.

The parallel port can be used for simple I/O similar to Mesa’s GPIO pins.

This page allows configuring and testing of the motor and/or encoder combination. If using a servo motor an open loop test is available, if using a stepper a tuning test is available.

Since at the moment PID settings can not be tested in PnCconf the settings are really for when you re-edit a config - enter your tested PID settings.

Specifically, when writing outputs, the LinuxCNC first converts the desired output in quasi-SI units to raw actuator values, e.g., volts for an amplifier DAC. This scaling looks like: The value for scale can be obtained analytically by doing a unit analysis, i.e., units are [output SI units]/[actuator units]. For example, on a machine with a velocity mode amplifier such that 1 volt results in 250 mm/sec velocity. Note that the units of the offset are in machine units, e.g., mm/sec, and they are pre-subtracted from the sensor readings. The value for this offset is obtained by finding the value of your output which yields 0.0 for the actuator output. If the DAC is linearized, this offset is normally 0.0.

The scale and offset can be used to linearize the DAC as well, resulting in values that reflect the combined effects of amplifier gain, DAC non-linearity, DAC units, etc. To do this, follow this procedure:

The scale settings can be directly entered or one can use the calculate scale button to assist. Use the check boxes to select appropriate calculations. Note that pulley teeth requires the number of teeth not the gear ratio. Worm turn ratio is just the opposite it requires the gear ratio. If your happy with the scale press apply otherwise push cancel and enter the scale directly.

Also refer to the diagram tab for two examples of home and limit switches. These are two examples of many different ways to set homing and limits.

Remember positive and negative directions refer to the TOOL not the table as per the Machinists handbook.

When using homing and / or limit switches LinuxCNC expects the HAL signals to be true when the switch is being pressed / tripped. If the signal is wrong for a limit switch then LinuxCNC will think the machine is on end of limit all the time. If the home switch search logic is wrong LinuxCNC will seem to home in the wrong direction. What it actually is doing is trying to BACK off the home switch.

The diagram should help to demonstrate an example of limit switches and standard axis movement directions. In this example the Z axis was two limit switches, the positive switch is shared as a home switch. The MACHINE ORIGIN (zero point) is located at the negative limit. The left edge of the carriage is the negative trip pin and the right the positive trip pin. We wish the FINAL HOME POSITION to be 4 inches away from the ORIGIN on the positive side. If the carriage was moved to the positive limit we would measure 10 inches between the negative limit and the negative trip pin.

If you select spindle signals then this page is available to configure spindle control.

This page is similar to the axis motor configuration page.

There are some differences:

This allows setting of HALUI commands and loading of ClassicLadder and sample ladder programs. If you selected GladeVCP options such as for zeroing axis, there will be commands showing. See the HALUI Chapter for more info on using custom halcmds. There are several ladder program options. The Estop program allows an external ESTOP switch or the GUI frontend to throw an Estop. It also has a timed lube pump signal. The Z auto touch-off is with a touch-off plate, the GladeVCP touch-off button and special HALUI commands to set the current user origin to zero and rapid clear. The serial modbus program is basically a blank template program that sets up ClassicLadder for serial modbus. See the ClassicLadder Chapter in the manual.

On this page you can add additional HAL components you might need for custom HAL files. In this way one should not have to hand edit the main HAL file, while still allowing user needed components.

The first selection is components that pncconf uses internally. You may configure pncconf to load extra instances of the components for your custom HAL file.

Select the number of instances your custom file will need, PnCconf will add what it needs after them.

Meaning if you need 2 and PnCconf needs 1 PnCconf will load 3 instances and use the last one.

PnCconf does its best to allow flexible customization by the user. PnCconf has support for custom signal names, custom loading of components, custom HAL files and custom firmware.

There are also signal names that PnCconf always provides regardless of options selected, for user’s custom HAL files With some thought most customizations should work regardless if you later select different options in PnCconf.

Eventually if the customizations are beyond the scope of PnCconf’s frame work you can use PnCconf to build a base config or use one of LinuxCNC’s sample configurations and just hand edit it to what ever you want.

Encoders will add < customname > +:

Steppers add:

PWM add:

GPIO pins will just have the entered signal name connected to it

In this way one can connect to these signals in the custom HAL files and still have the option to move them around later.

The hidden preference file is in the user’s home file, is named .pncconf-preferences and require one to select show hidden files in your file manager to see and edit it or on the command line you use ls with the -a option. The contents of this file can be seen when you first load PnCconf - press the help button and look at the output page.

Ask on the LinuxCNC mail-list or forum for info about converting custom firmware. Not all firmware can be utilized with PnCconf.