Help me understand this simple schematic

[RB211]

I am starting to think that I made a stupid assumption that the opto-isolator was part of the internals of my servo driver and not part of what should be inside of my custom cable I made. My servo drive refuses to reverse direction when the relay closes for the VFD/Spin Reverse connection. The input needs 5v, and it looks like it gets it from pin 22 via the 2k voltage drop resistor which I did include(250$ mistake if I didn't). I never connected Pin 10 to a 5v source of any kind because I believed that was internal, but it isn't? The Enable pin does work when the relay closes because it is set to Active Low and all it needs to do is complete the circuit to ground or common.
I think I answered my own question, but I would like to hear from the collective brain trust here for its opinion. Can I get away with a simple diode? Or even a LED from pin 22 to pin 10 on JP4?

[J Tiers]

It appears from the schematic that the "DIR" input (direction, presumably) is an optocoupler isolated input, requiring a low on pin 10 and current into pin 22 for one direction, and no current in for the other..

Only one optocoupler should be needed, but there is no harm in having the two, as long as OC5 can drive the LED of the second opto. A simple transistor would work as well, but the two boards are each configured so as to avoid problems with signals and grounding, by using optocouplers. That is why the drive opto has it's input "floating" and not connected to power or ground on that board. The opto provides isolation between the controller and drive.

Not sure why you are asking about diodes or an LED on those pins, when there is an opto that simply needs a drive input. The input could be a high on pin 22, or a low on pin 10 (with appropriate limiting resistor). You show it as a low on pin 10.

As mentioned, the existing opto setup should work fine as shown if the controller opto can sink the current the drive opto needs to make it switch states from open to closed.

The only issue might be a polarity problem if FWD on the controller provides REV on the drive. If not programmable, the connections can be changed to accommodate that.

[JRouche]

Ill be the first to say. That in no terms is a schematic. Not even a block diagram in my opinion. It is missing so much as to leaving it up to interpretation.

I can do, or try.. The opto isolator? Do you need it? If so the I think you may have a bad component.

I do like the circuit Mr. JR

[JRouche]

internals of my servo driver and not part of what should be inside of my custom cable I made.

See, here is the problem. JR

[RB211]

It appears from the schematic that the "DIR" input (direction, presumably) is an optocoupler isolated input, requiring a low on pin 10 and current into pin 22 for one direction, and no current in for the other..

Only one optocoupler should be needed, but there is no harm in having the two, as long as OC5 can drive the LED of the second opto. A simple transistor would work as well, but the two boards are each configured so as to avoid problems with signals and grounding, by using optocouplers. That is why the drive opto has it's input "floating" and not connected to power or ground on that board. The opto provides isolation between the controller and drive.

Not sure why you are asking about diodes or an LED on those pins, when there is an opto that simply needs a drive input. The input could be a high on pin 22, or a low on pin 10 (with appropriate limiting resistor). You show it as a low on pin 10.

As mentioned, the existing opto setup should work fine as shown if the controller opto can sink the current the drive opto needs to make it switch states from open to closed.

The only issue might be a polarity problem if FWD on the controller provides REV on the drive. If not programmable, the connections can be changed to accommodate that.

So that opto-isolator is internal to the drive? When I drive pin 10 low, the drive does not reverse. It slows down and stops responding to any analog speed change requests.

[Jerrythepilot]

You have 24 volts positive going to the 2K resistor. Then it goes into the optoisolator in the servo drive. The led in the optoisolator doesn’t activate until the optoisolator in the Acorn controller is activated, which brings pin 10 down to ground. I would read the voltage between pin 22 and pin 10. 5 volts, drive is being commanded to reverse. Zero volts, no command to reverse from controller. A temporary jumper from pin 5 COM to pin 10 should force the drive into reverse, The way this is drawn I agree with you, the optoisolator should be internal to the drive. Adding a diode or led wouldn’t work. The led in the optoisolator triggers the output to conduct. In the Acorn controller it is energizing its optoisolator to close the wire from pin 10 in the driver to ground.

[Noitoen]

Dir+ and Dir- doesn't mean clockwise and anticlockwise direction. It is there to be universal. Some controllers use positive signal and so you connect the Dir+ to the positive and feed Dir- with a Gnd signal. And viceversa. The servo will change direction when the signal disappears

[Noitoen]

So that opto-isolator is internal to the drive? When I drive pin 10 low, the drive does not reverse. It slows down and stops responding to any analog speed change requests.

That is done by the enable input.

[JRouche]

The led in the optoisolator doesn’t activate until the optoisolator in the Acorn controller is activated,

I think I got on the wrong page./ Really like the circuits you have shown.

I might use optical isolators a lil different then you do. I am trying to work with others, I hate that. Anyway, high speed stuff.

Optical High Speed, AKA. Laser optical isolators. Think space craft. JR


Edit: The weight, no glass lens at all. For any of the systems, glass was out, pissed some folks off. JR

[polaraligned]

Can I get away with a simple diode? Or even a LED from pin 22 to pin 10 on JP4?

No. That is an optoisolator shown and it is integral to the servo drive. You just supply the +24v and the 2k resistor.

[JRouche]

Oh? For my own personal interest ? I am here just for fun, Its working,, JR

[rdfeil]

Read the notes on the page. It is a REALLY POOR set of information. I am thinking is MIGHT IMPLY that the analog input signal needs to be reversed to reverse the direction. In any case I would begin by trying to force the direction to reverse. Apply an analog input for any speed and apply a ground to pin 15 (ENA) and leave pin 10 disconnected. The spindle should run. Note the direction. Next ground BOTH pin 10 and pin 15 with the same analog input signal. The spindle should run in the opposite direction. If it does not then their is either a setup issue in the driver or the driver is defective. What you have described yourself doing should NOT have done any damage.
Let us know what you find.

[mikey553]

I do not understand everything you said in your first post. What relay are you talking about?

It appears you have 3 major components: 24V power supply, Acorn controller and DYN4 servo drive. By default Pin 22 of the servo drive receives 5V from the power supply via voltage dropping 2K resistor and it spins the motor in the forward direction. If Acorn controller commands to reverse, its internal transistor conducts the current from Pin 10 of the servo drive to ground and the voltage at Pin 22 of the servo drive becomes 0V as well. So it can be 5V or 0V at Pin 22, this is how the drive knows which direction to go. You can check the Pin 22 voltage and see how it behaves during forward or reverse commands. I would not mess with the drive or controller, they are either good or bad.

[J Tiers]

So that opto-isolator is internal to the drive? When I drive pin 10 low, the drive does not reverse. It slows down and stops responding to any analog speed change requests.

It is shown as internal.

it is listed as a PULSE input in the only manual I found. You may not be supplying it with the correct input for the mode selected.

But page 34 shows the inputs required, which seem to depend on the mode selected. You have the choice of "pulse + Direction", "A/B quadrature", and "CW + CCW" .

The pulse formats are entirely different for each, as you can see. The first is what you expected, the second is a pair of pulse trains, and the last is pulses on one OR the other of the inputs.

https://www.dmm-tech.com/Files/DYN4MS-ZM7-A10A.pdf

[RB211]

It is shown as internal.

it is listed as a PULSE input in the only manual I found. You may not be supplying it with the correct input.

https://www.dmm-tech.com/Files/DYN4MS-ZM7-A10A.pdf

Ok, another clue is that it is calling out OC5 on the Acorn specifically, but OC5 also controls relay 5 on the external relay board, perhaps it really does matter that I use the internal OC5? Right now relay 5 is Enable.
Another possibility is that my PID for the servo is so jacked up right now that it can't reverse.