Mori MVJR Build Log

The 7I64 outputs are not short circuit protected so if you turn an output switch on into a shorted load you can damage a single output (you can avoid this with a fused power supply)

But it is hard to see how you could damage any other outputs.

(any amber lights that turn on (indicating a ON output) are turned on by EMC, no output will turn on unless commanded to so unless the "bad" 7i64 is connected to the same 7I44 jack as the one with the amber lights, this is not diagnostic )

It went like this:

12V+ power supply > e-stop (normally closed)

e-stop > relay

relay > 7i64 out pin 13 1st position

7i64 out pin 13 2nd position > Ground


I made the same connection to another 7i64 and it is working fine.

Is there a flyback diode across the relay coil (and is it polarized correctly)

If the other pins on the board aren't working, can you think of anything that I could have done wrong that would burn it out?

I guess I could try switching the CAT cables between the 7i64s to make sure it isn't something upstream.

If that doesn't change anything I guess I will order a new board. I'm just worried that I am doing something wrong that will burn out other boards.

I can not think of anything you could do externally to the field I/O (the inputs and outputs on the terminal blocks) that would cause this, except perhaps a dead shorted output and even that is most likely to just damage one output

Definitely try swapping cables (plug the possibly bad 7I64 in the 7I44 jack that the working 7I64 is plugged into)

If there is something wrong with a 7I64 we will issue a RMA and replace it (Monday)

I changed the connections to the 7i64 and moved the pin to another open pin and it is working now.
I had several open pins so I am good to go. Now the maber lights are working too.

One symptom, that might be informative (or not) is I connected my fluke circuit tester to the in and out of the pin I was having trouble with.
When the machine was off, it read 195 ohms, (I'm not sure what scale)
When the machine was on the pin was open, I was expecting it to ber closed, but I'm in over my head on this stuff.

Anyhow, I'm making progress again, hope to report more good news soon.

Thanks

Good, It makes more sense that only one output would be damaged

Did you understand what I meant about the flyback diode?
Inductive loads like relay coils may have a flyback diode connected across the
coil to clamp the inductive turn-off spike. If a flyback diode is installed, the positive side
of the relay coil will connect to the diode cathode (end marked with band)

So you have to be very careful that you have them connected with the correct polarity
or they will be a direct short when you try to power them.

Maybe a good thing would be to try all output circuits by applying the appropriate voltage directly
(say your 12V directly to the relay coil + side) with maybe a fuse in series with the power. just to verify that you dont have a shorted load anywhere.

I did have a flyback diode on it, but I may have had it on the wrong direction.

I took it off and haven't put it back on, it seems to be working fine, should I put the diode back on or leave it off?

Today was a really good day, all the encoders are working and reading properly!

Over the next few days I hope to get the servos turning the drive motors and the homing working.
My goal is to have it running (except the tool changer) by Thanksgiving.

The more I look at EMC, the more impressed I am. It is really a fine piece of work with so many diagnostic tools.

One thing I was wondering, in addition to the single limit/home switches, on each axis, the machine also has proximity switches that allowed it to rapid until it was near home then approach home slowly, I didn't find anything to support the proximity switches in the homing examples, I wonder if anyone has been able to use them, if not' I'll just forget about them, considering all the other advancements, this is trivia.

Flyback diodes are not required with the 7I64 outputs but they do reduce the switching noise. If you have no flyback diode, when the 7I64 output turns off, you will get a ~90V spike across the coil.) This ~90V spike can couple to nearby inputs, so in general its better to leave the diode on but just check the polarity carefully (and make sure the diodes are OK)

If one end of the coil is grounded, that end of the coil needs to connect to the diode anode.

if one end of the coil connects to +12 this end need to connect to the diode cathode (band end)

Basically the diode is connected so that is is reverse biased when the coil is energized (cathode to + anode to - )