Retrofitting a 1986 Maho MH400E

I installed the PC, the EXE and the 7i84, so now it is wiring wiring wiring...
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Unfortunately I cant find my bag of heat shrink.

First up, I just wanted to wire up the 5V to the 7i77, and the field power to both 7i77 and 7i84. I found an error in my wiring revisions. I had planned to wire both those boards to the +24V rail at terminals 200 (+) and 201 (0V). Checking the wiring diagram, there are three 24VDC rails. The one I choose isn't powered until the E-Stop chain is closed.


Since not all MESA pins are reported through the HAL if field power not applied, I am picking that this configuration would cause a LinuxCNC loading error for missing pins.

The 7i77 and 7i84 field power needs to be moved to that other rail between terminals 204 (+24) and 201 (0V), to ensure that they are always powered. Also, I added a field power connection 7i84 TB1-3 to power the second bank of connectors, which I missed before.

Once I get the MESA boards powered, then next step will be to wiring up a temporary E-Stop and Machine on buttons, and configure those HAL functions.
Mark

drimaropoylos wrote: The problem is that the limit snitches are hard wired to the estop circuit, so when they activate, they power off everything.
John

Well, then you need to add additional switches within the span of the limits for the homing.

Jon

They came up really nice.
John

We do have some experimental firmware for the 7I84 that allows startup and input to work without field power
(just VIN), so you could wire the 24V that's available only when out of EStop to the field power

It does require that the input thresholds be set via LinuxCNC hal pins
since it can't depend on field power being present.

If it works out we will add the option to the 7I76 and 7I77

drimaropoylos wrote: The problem is that the limit snitches are hard wired to the estop circuit, so when they activate, they power off everything.n

You _could_ add a relay to bypass the e-stop and powered by logic around the axis.N.is-homing HAL pins.
Whether you _should_ is for you to decide

Thanks for the heads up on that 7i84 experimental firmware, but sInce it is an easy task to just move the wiring from terminal 200 to 204, I will do that. I am still a real newbie with the MESA and HAL set up, so I'd rather not pursue too many alternative options.

Mark