Help needed, 7i77 I/O and Servo I/O

Sorry for the many postings lately, I just have the overwhelming feeling that I may fry something if I am not certain I wire it up right.

I understand that the 7i77 supplies field power on the output terminals, when active.
Also, the 7i77 senses field power on the inputs, to activate.

The outputs on both types of servo drive I use, have DO+ and DO- terminals, which seems fairly straightforward to wire.
But just to make sure, if someone can review what I have, I would REALLY appreciate it.
First, the delta drives.

In this example, the Resistor/load would be the 7i77. The field power would connect to DOX+ and 7i77 input pin would connect to DOX-
The "load" (7i77) would be on the ground side of the circuit, opposite of the example. (Not sure if this is correct, but I am guessing it is, as the DMM picture shows it this way, and it uses photocoupler outputs, looks like a transistor on the delta) Please correct me if I am wrong!


In this example, field ground would connect to COM+ and 7i77 output pin would connect to servo DI pin.
This seems fine, makes sense to me. However when digging further into the delta manual, I find this:


Now I am confused! The example shows COM+ being connected to power supply ground, for "PNP transistor, common emitter (E) mode, (SOURCE mode)"
This is the previous example I just listed (delta diagram2.jpg). However it clearly says that COM+ is to go to external power, and COM- is to go to external ground.
Also, it says that COM+ is common with the digital output voltages, but they have their own + / - terminals. WTF?!

I don't know how anybody does this for a living? Of course I emailed delta global technical support, and called their local office, but I am not expecting a reply since I am not a multi-million dollar operation.

Thanks for any and all help that anyone has to offer.
I will be posting examples for my DMM drive in another post to avoid information overload.
Thanks again.

The Delta output to 7I77 input looks right (and its hard to damage the 7I77 inputs outside if putting 120/220VAC on them)

It looks like the Delta inputs use AC OPTOs so are not sensitive to polarity in
which case COM+ goes to field GND (common) and SON etc go to 7I77 outputs

Thanks a lot, makes me feel better.
Im working on my post for the DMM drive, unfortunately it's manual is lacking in important information, so I might have to wait until I get an email from the creator explaining it further.

Ok, now on to the DMM Dyn3 drive.

The outputs appear to be exactly like the Delta drives, so I will use that arrangement.

Here is a diagram from the manual showing digital input wiring
I believe the diode shown in the drive connected to EXT +24 is a misprint, should be reversed, and possibly missing a diode on the EXT+12 line.


This would be fine if I had active low 7i77 outputs (I cant do that right?)
Further in the manual there is a diagram showing + voltage being switched, but no Pin assignments shown.


Now that I write this out, I realize there is no chance of anyone who didn't design this drive being able to know for sure how it is supposed to be wired.
Without labels on the pins, I am just left guessing.

Hopefully I will get a response from the creator of the drive soon, and I can get this wired up.

PCW Thanks for your help..

btw, I have a product idea for you.
A rj45 breakout board that plugs into the encoder terminals on the 7i77.
I will try to make my own, with jumper wires to the 7i77, and to the servo drive, to simplify wiring, and make less chance of mistakes in case I ever have to remove or change any components in the future.

That is, unless you think that is a bad idea.

alan_3301 wrote:

Ok, now on to the DMM Dyn3 drive.
.....
btw, I have a product idea for you.
A rj45 breakout board that plugs into the encoder terminals on the 7i77.
I will try to make my own, with jumper wires to the 7i77, and to the servo drive, to simplify wiring, and make less chance of mistakes in case I ever have to remove or change any components in the future.

That is, unless you think that is a bad idea.

Unless you are talking about RJ45 to 3.55mm pluggable, similar devices to this: is 5-15$ on ebay or even cnc4pc. I'm sure you could find something similar at a local electronics hobby/supply store for about the same price.

andypugh wrote:

One that plugged into the smart-serial terminals would also be rather handy.

One like that could be used on the 7i85 cards to make them easier to inteface an be more like the 7i74 in ease of hooking up. At least for the sserial ports it makes sense.

Anders

I was thinking something like this.
I understand it would be a huge job to produce these, but thought I would throw it out there.

For the DMM enable inputs you can use the enable output OPTOs on the 7I77
Since these are uncommitted OPTO transistor outputs, the can be used for
pullup or pulldown (sourcing or sinking) applications.

Note the the 7I77 enable outputs 1..4 are used for motion axis and output 5 is used for spindle

For sensing sinking outputs, you can use an external 2K pullup resistor