MSD043A1XXV Panasonic AC Servo Driver 400w - MB3 connection help

You're doing well Doddy! I spent 16 years working out how to produce clear, easily understandable explanations of electronics stuff and it's not as easy as you think it is.

Nemo1966,
Never be embararrased to ask the simplest questions. I guarantee that there will always be a dozen or more other people thinking "I wanted to know that but was afraid to ask".

The only thing I would add about open collectors is that they are designed to be flexible. Unlike an output which switches from 0-5V, 0-12V etc. which restricts the voltage used by the external device, an open collector (especially the more common NPN version) can be used with any external device within the voltage and current capability of the transistor regardless of the supply voltage used by the device containing it.

Kit

OK - saw another diagram in the MB3 documentation that I *think* helped me. This is what I have:
Do I need more? Or should the the 24v going to the controller be sunk to a ground like the cabinet chasis frame (with a relay)? Like the old 2 stroke motorbikes?
Attachment 28751

I am also struggling with:
Attachment 28752


Any help is really appreciated

Edit: I will be adding diodes to the 24v supply to driver as wrong polarity can damage it apparently.

Your diagram is a little confusing - thoughI think I know what you're trying to do.

It's F1 Qualifying on TV just now - and hour for me to snooze, I'll sketch something for you after that.

The indicated dotted ellipse - that's indicating a screen on the cable to reduce EMI (often a braided sheaf under the first layer of insulation).

The question on pin 12 - "Equiv to EN on servos" - kinda - but it's more the command to the servo controller to start/enable the servo. It looks to be pulled low to be active. Page 11 indicates the internal equivalent circuit - another example where you can use the open collector output from the MB03 directly (no need for a relay).

EDIT:

This is how I'd be connecting the MB3 to the servo controller...

Attachment 28757

So, you have a common 24V supply to the Servo controller and the MB3 card. That's all good. The internal circuitry of the Servo controller, as page 11 ...

Attachment 28760

Shows that pin 12 is connected to the side of the internal Opto isolator that needs to sink to ground to enable it - that's the signal path that you're providing with the MB3.

So far you've discussed the servo enable line, step and direction signals, there's every chance you'll have to look at some of the other inputs as well, or you may need to ground them (read up about each of them).

Quote:

---

Originally Posted by Nemo1966

Edit: I will be adding diodes to the 24v supply to driver as wrong polarity can damage it apparently.

---

I'm curious what you meant by this - give us a sketch.

As per pic... as I was going to add a relay to control what I thought was the equivilent of the Stepper "Enable" I was going to do the same
I was looking at note 2 and 3
Attachment 28761

Okay, if you'll forgive the explanation. The information in the manual is accurate, but again, doesn't particularly try to educate the reader. I think you're looking at 2 + 2 and getting 5 - please don't be offended by that.

Note 2 in the diagram ("Please pay attention for the polarity of VDC. Reversed polarity of the above fig. will damage the driver") is to ensure that you connect 11 and 28 to +V and ground, respectively. You *could* put a diode in series with one of these, but to get the diode right you pretty much have to have wired it correctly anyway. So to me the diode is a little superflouous.

Note 3 in the diagram ("When you directly drive a relay with each output signal, please install a diode in parallel to the relay as the above fig. shows. If you do not install a diode or install it in reverse direction, the driver get damaged") refers to a completely different beast. Inductive loads (the relay coil is one) have a behaviour which, energised creates a magnetic field (in fact, that's how the relay switches - it's an electromagnet that attracts the contactor that provides the electrical switch). When the driving power is removed from the coil, the electromagnetic field collapses, inducing a voltage into the coil of the relay. This flows in reverse and is proportional to the speed at which the driving current is removed - fast = big voltage. This can present a voltage at the OUTPUT of the servo controller that far exceeds the 24V you've connected, and destroy the circuitry. The purpose of the diodes in the diagram you included essentially clamps that current flow between the coil and the diode - safeguarding the servo controller.

So, in that diagram, the diodes are not really to protect wrong polarity, but to protect the servo controller from what's referred to as back EMF.

Fun experiment: Get a relay, connect the coil to 12/24 V as appropriate. Put your fingers (on one hand if you want to be semi-safe) across the two pins of the relay coil, then remove the power from the relay coil. Make sure you're not within striking distance of anything fragile... or hard.

No offence taken in any way - glad to learn whatever I can.

Thanks for the clarification - much appreciated.

Processing..... :dread:

Seems I may reading more into the diagrams than needed.

So looking at the Servo On diagram you posted... then looking at this:
Attachment 28763

Then I just do the same for the other pins and make the hi or low accordingly?

Quote:

---

Originally Posted by Doddy

Okay, if you'll forgive the explanation. The information in the manual is accurate, but again, doesn't particularly try to educate the reader. I think you're looking at 2 + 2 and getting 5 - please don't be offended by that.

Note 2 in the diagram ("Please pay attention for the polarity of VDC. Reversed polarity of the above fig. will damage the driver") is to ensure that you connect 11 and 28 to +V and ground, respectively. You *could* put a diode in series with one of these, but to get the diode right you pretty much have to have wired it correctly anyway. So to me the diode is a little superflouous.

Note 3 in the diagram ("When you directly drive a relay with each output signal, please install a diode in parallel to the relay as the above fig. shows. If you do not install a diode or install it in reverse direction, the driver get damaged") refers to a completely different beast. Inductive loads (the relay coil is one) have a behaviour which, energised creates a magnetic field (in fact, that's how the relay switches - it's an electromagnet that attracts the contactor that provides the electrical switch). When the driving power is removed from the coil, the electromagnetic field collapses, inducing a voltage into the coil of the relay. This flows in reverse and is proportional to the speed at which the driving current is removed - fast = big voltage. This can present a voltage at the OUTPUT of the servo controller that far exceeds the 24V you've connected, and destroy the circuitry. The purpose of the diodes in the diagram you included essentially clamps that current flow between the coil and the diode - safeguarding the servo controller.

So, in that diagram, the diodes are not really to protect wrong polarity, but to protect the servo controller from what's referred to as back EMF.

Fun experiment: Get a relay, connect the coil to 12/24 V as appropriate. Put your fingers (on one hand if you want to be semi-safe) across the two pins of the relay coil, then remove the power from the relay coil. Make sure you're not within striking distance of anything fragile... or hard.

---

I found this for a MB3 to a panasonic A series.
Attachment 28764

Seems literally just the "servo on" for that one - as you posted in the modified picture.