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Mach4 Reference axes with shared limit and home switch
« on: August 05, 2017, 07:00:58 AM »
Running mach4 3390 on wx4 screen. When I click the Reference All Axes button the homing cycle starts, but is interrupted by the limit switch being triggered. Is there a way to tell Mach4 to disable the limit switch inputs while homing? I use the same switches for homing and limits, and this setup worked perfectly on the version 2803 which I had before I upgraded. Any ideas on how to solve this?
Re: Mach4 Reference axes with shared limit and home switch
« Reply #1 on: August 07, 2017, 08:21:30 AM »
I'm currently running Mach4 V3390 with the HiCON Integra motion controller.  My Y axis has 1 switch for Y++ (This acts for Y-- as well) and Y Home.  IT all works correctly.
Chad Byrd
Re: Mach4 Reference axes with shared limit and home switch
« Reply #2 on: August 08, 2017, 06:37:43 PM »
I think the plugin determines what you can do and how it determines if its a limit or home switch.
Using Pokeys57CNC you use the plugin config PE axis set-up for common home-limit switches. 

Offline mark4

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Re: Mach4 Reference axes with shared limit and home switch
« Reply #3 on: August 13, 2017, 12:04:17 AM »
hi what controller are you running. mach has had the capability of having the same home and limit switches for ever as it only homes one axis at a time. so how do you have the limits/home configured. the easiest way to tell is to go into the diagnostics screen watch inputs and home trip a switch and see what leds light up
Re: Mach4 Reference axes with shared limit and home switch
« Reply #4 on: August 13, 2017, 09:26:26 AM »
Mach4, and to my knowledge, all controller manufactures support using the
same switch as both a limit and a home switch. For those controllers which
rely on the internal Mach4 dialogs for home and limit switch configuration,
this is done by putting duplicate controller and input signal selections
into multiple lines in the Config > Mach > Inputs Signals configuration
dialog for each possible use of the signal. With Mach4 an input signal can
be read by multiple processes.

Output signals on the other hand can have only one process controlling
them and an output signal that has been configured in one line of the Output
Signals table will no longer appear in the drop down box for output signal
selection. If you are trying to use an output signal and cannot find it,
check to see if something else has already claimed it.

Mach4 can also support homing multiple axes at the same time. It is up to
the controller manufacturer to be able to do this. Again, to my knowledge,
I think most can do this. PMDX supports this.

Remember that all Home and Limit switches are associated directly with
Motors. Their relationship to axes is under control of the Axis Mapping
to the motors with the dialog at Config > Mach > Axis Mapping.

Mach4 can home the axes in the order that you specify. It is common, by
example, for wood routers to home Z first, followed by X and Y at the same
time. This makes sure that the cutter will not hit any fixtures during
homing but still minimizes the time needed by homing X and Y at the
same time. The order is controlled in the Config > Mach > Homing and
Soft limits dialog. Each axis to be homed must have homing enabled.
Do not enable homing for axes that do not exist. Set the homing
order number for axes that you do not wish to home to be 0. Set the
homing order to 1 for the first axis to be homed. Set axes that should
home at the same time to the same number.

Axes that do not have a corresponding home signal and need to be declared
as homed without moving them should have the Home In Place feature enabled.
It is common to do this for a rotary axis where home depends on aligning
the material correctly in the rotary device instead of looking for a home
switch. Many people also run wood routers with all axes set for Home In Place
and simply place their stock on the table and jog to a convenient zero point
before clicking on Ref All Home. In this case home is wherever you put it.

One thing that will not work properly is to wire the machine and configure
Mach4 such that any home or limit switch triggers an Emergency Stop. This
will halt the machine and de-reference the homing status of all axes.

When diagnosing a homing problem I suggest using the controller's test
capabilities to see the signals, either as physical LEDs or as indicators
on a software display panel, to verify that the signals are being seen by
the hardware. PMDX controllers use a display panel launched using the
Config > Plugins > PMDX SmartBOB dialog. This panel is a floating window
that can be moved to the side and left active after closing the config
utility so that it can be seen while running other tests.

Next use the Machine Diagnostics panel in Mach4 to verify that Mach4
sees the signals as the functions that you intended to define for each
signal input. Switches configured for multiple meanings will cause multiple
indicators to light at the same time. This is normal. This process helps
verify that you did enter the setup data correctly and that you have
the Axis to Motor mapping configured as you intended. If an Axis uses
slave motors, think gantry axis driven by tandem motors, then all motor
home signals for that axis must the triggered before the Axis Homed
indicator will come on. The signals will be considered individually by
the homing routines, only the display requires all associated signals to
be active.

Hopefully the descriptions above are more informative than confusing.

Steve Stallings
« Last Edit: August 13, 2017, 09:29:27 AM by Steve Stallings »
Steve Stallings
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