Retrofitting a 1986 Maho MH400E

Hi John,

Thanks for the suggestions. I removed the 3SH1 wire from the 7i77 input and changed the config to allow for software estop release. However, the problem remains the same - when I press the physical button to switch on the relay and then press the machine on button in LinuxCNC, the machine powers off as soon as I release the 3SH1 physical button.

The hard limits are trapezoid-shaped pieces of metal bolted on to the machine. When the buttons I posted earlier touch the the metal, the switch engages triggering an estop.

The Z encoder now moves, but I'm still unable to get the energized drives to stay on when I release the button. I checked the wiring numerous times to no avail so I decided to play with the config a little.

I commented out the two lines which connect the machine-is-on signal that gets outputted to the GUI through halui. One of the lines is for the 19K1 relay through an output pin on the 7i84 and the other is for releasing the Z axis brake.

The interesting thing is that if I comment out the Z axis brake release, then pressing the machine on button doesn't energize the drives. But when I comment out the 7i84 output signal for the relay, there's no change in behaviour vs when both lines are active. There seems to be something wrong with that output to the relay. I'll try switching it to another pin.

The card itself seems to work, it lights up green on LCNC start and you can see all the pins in hal. The wire isn't loose, that's one of the first things I checked (repeatedly, hoping against all hope that doing the same things a few times will have a different result at some point).

Update: yup, the 7i84 was the cause. I switched the wire over to 7i77 output 01 and changed the hal line and now the drives latch on, with all the encoders working. Only X is jogging in the wrong direction.

I tried a different output on the 7i84, but no dice. There's a whole bunch of stuff on that card, anybody have any ideas on how to troubleshoot it?

I don't think I'd be able to get all the ribbon wires to the 7i77 even if I wanted to (which I don't). Should the diode next to the RJ45 socket on the 7i84 be green, or is it okay if it's orange? It's got 24V field power and has all the pins showing in hal, so what gives? I set it up to work in mode 1 for voltage output capability but that doesn't change anything. More frustratingly, it did work before (even this morning). What the heck did I do to it?

Do you have _both_ ( A&B ) field power connections on the 7I84?

I'm giving it TB-1 and TB-8, and the CAT5 cable. I see that there should be another connection for the other bank, but output-08 was on TB-2, which according to the manual should have been powered. What else do I need to connect?

You need all power connections

Thanks, I wired TB1-3 to the same 24V power supply so it should have the power now (ground is common so I needed just the power, right?). But it doesn't solve the problem, when I connect the wire to TB2-17, which is output 8 and have hal do the following:

net machine-is-on hm2_5i25.0.7i84.0.2.output-08

The drives don't stay powered after I release the button. Whereas when the same wire was connected to an output on the 7i77, everything worked fine. In fact, as I said before, both yesterday and today morning it worked with the 7i84.

EDIT: it's acutally 7i84.1.5.output-08, since it goes through the 7i74.

I checked it with a meter and it shows 24V on both TB1-1 and TB1-3.

What output is the 7I84 (now 7I77) driving and does it have a flyback diode?

I'm concerned that if a 7I84 output is damaged you may also damage the 7I77

Also make sure that no field power to 7I77s or 7I84s is switched by a relay or mechanical switch. This can damage the output drivers (the field power should be wired directly to the field power supply or via a fuse, never a relay or switch)

Intead of choping the ribon cable ,you can use something like this.