Mesa setup page:

Configuration Tab:
    Allows you to choose the firmware,
    number of components / number of gpio, 
    frequency of pwm / pdm and the watchdog timeout.
    The base frequency should be set as per the Mesa daughter
    board you are using. Different boards require PDM vrs PWM
    which is set on the connector tabs. 
    pick the firmware you wish to use and 
    you will see the component numbers change   
    default is to have all the available components active. 
    by choosing less of each component frees up gpio
    press 'accept component changes' to have the connector 
    tabs reflect the changes
    Any signalnames you had already pick will be lost unless 
    the component is the same as before the change.
    Depending on the board chosen, the connector tabs will disappear
    if not available.
    Sanity checks are available for some boards - these just remind you to
    check some settings that are specific for the chosen board.
    The help page output tab will show the firmware PIN file,
    which shows the default components, their channel number
    and their Component number. The component number is useful for
    changing some options such as stepper output pins to open drain.
    For instance: in firmware SVST8_4 to change stepper channel
    0 to open drain outputs, find out their component numbers.
    step IO number = 48
    direction number = 49
    In your custom HAL file add the commands:

    setp hm2_5i20.0.gpio.048.is_opendrain true
    setp hm2_5i20.0.gpio.049.is_opendrain true

    note that this says GPIO but the component number corresponds
    to the stepper outputs. See the manual for more options.

    If you are using the 5i25 card with 2x7i77 or 2x7i76 firmware
    but are only using one daughter board, deselecting half the components
    (including half the sserial channels) will free up the extra
    5i25 connector for GPIO, if desired.

Connector Tabs:
    The available tabs are selected based on the 
    mesa card type.
    The available component types are based on the 
    firmware / component number selected on the setup page.
    The tabs will display the signal names and the component
    types.
    There are different pintypes depending on the components 
    available in the selected firmware:

     GPIO - general purpose input / output
        This is for general digital control.
        If selecting mainboard GPIO, you can select the type 
        in the pintype combobox
        This includes GPIOI - input, GPIOO - output, and 
        GPIOD - open drain output
        The available signals will change if you switch between 
        GPIOI and GPIOO/GPIOD.
        Sserial daughter boards GPIO type is not selectable.
        In general, mainboard GPIO is updated faster then sserial GPIO.

     ENCODER - a hardware base quadrature counter

        You select the A phase signal and the rest of the 
        phases (B, I, and possibly M) are automatically included.
        If using a single input or single input and index for the spindle
        encoder, the encoder must be put in 'counter-mode'. This must be
        manually added in a custom HAL file. For example (changing the board 
        name and encoder number to your requirements):

        setp    hm2_7i43.0.encoder.00.counter-mode 1 

        HAL file. See the Hostmot2 section on encoders for more info about 
        counter mode.

     MUX ENCODER - a hardware base quadrature counter

        You select the A phase signal and the rest of the 
        phases (B, I, and possibly M) are automatically included
        Mux encoders allows two encoders per set of pins by using
        a select pin to choose a second set of encoders. This
        component is used with firmware that requires a special
        daughter board from Mesa. Remember when connecting encoders
        you must use the pinout for the daughter board.

     RESOLVER - a resolver encoder counter
        used with MESA 7i49 daughter board with special firmware
        Some servos have resolvers rather then quadrature encoders

     PWMGEN - a hardware base pulse width (or density) 
        modulation generator

        You can select:
        PWM -pulse width modulation using pulse and direction output pins
        PWD -pulse density modulation
        UDM -pulse width modulation using up and dowm output pins
        you select the PULSE signal and the direction and enable 
        signals are automatically setup.
        Please see the Mesa daughter board documentation for the most up-to-date
        recommendations for frequency and type. Here are the common ones: 
        The 7i33 daughter board requires PDM @ 6 MHz.
        The 7i78 daughter board (for the 5i25) requires PDM @ 5 Mhz.
        The 7i29,7i30,7i40 require PWM @ 20 KHz
        the 7i48 and 7i49 require UDM @ 24 KHz

     3 PWMGEN - special pwm generators used for driving brushless
        servo motors 3 windings directly.
        This is not fully supported yet so the HAl file will need
        commands added to it to finish the config.

     STEPGEN - a hardware based step and direction generator

        only step and direction stepgens are supported
        You select the STEP signal and the direction and enable
        signals are automatically setup
        If you wish to have a slave stepper for a tandem axis
        select a master axis and a tandem axis.
        The tandem axis will be connected to the master axis command signal and
        will be set at all the same settings as the master axis stepper, so the
        stepper/driver should match. There is no facility to align these steppers
        while homing, the slave simpily follows the master's command.
    
     POTENTIOMETER - A digital potentiometer used primaraly to control
        a spindle found with sserial card combo 5i25/7i76

     SSERIAL - smartserial daughter boards communication stream.
        allows connection to many daughter boards.
        Currently PNCconf recognizes:
        7i64 I/O board
        7i69 I/O board
        7i70 I/O board
        7i71 I/O board
        7i76 I/O board works only with the 5i25 main board
        7i77 I/O board works only with the 5i25 main board
        7i78 breakout board works only with the 5i25 main board
        8i20 amplifier ( untested )
        Linuxcnc supports 4 ports of 8 channels each of sserial
        PNCconf only configures 5 channels of port 0 (so max 5 sserial boards -
        note that some 5i25 daughter boards use some of the sserial channels 
        internally.)
        Note that some daughter boards use multiple sserial channels.

    You could change these options in a custom HAL file
    If you wish to connect a component to something in a 
    custom HAL file write a unique signal name in the combo 
    entry box. Certain components will add endings to your 
    custom signal name.

    Encoder will add < customname > +:
    -position
    -count
    -velocity
    -index-enable
    -reset

    Steppers add:
    -enable
    -counts
    -position-cmd
    -position-fb
    -velocity-fb
    
    PWM add:
    -enable
    -value

Signal selection:
    By selecting signals you are configuring the input and output
    of the mesa boards and selecting how pncconf displays options
    in the upcoming pages.
    PNCconf can configure servo motors, open loop steppers and
    closed loop steppers.
    PNCconf does a sanity check when you push the next button.
    It checks for some obvious problems such as:
    if you select a PWM signal for an axis PNCconf assumes you
    are using a servo motor (except for the spindle)- then you 
    need to select an encoder signal too.
    If you select an encoder you must select an PWM or a stepper
    signal as well (except for a spindle)
    A dialog will pop up letting you know of these detected errors.
    PNCconf will not catch the error of setting two components 
    the same (If fact for GPIOO outputs this is fine anyways)
 
    For testing purposes if you require an output true, for instance to force
    a relay to close to allow the amplifier to be powered, select the 
    'force-pin-true' output signal. The openloop and tuning tests will then
    set the output true for the length of the test. 


    
