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Oriental Motor / Vexta stepper motor and driver

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Mads Barnkob

Wed Apr 27 2016, 07:25AM

Registered Member #1403 Joined: Tue Mar 18 2008, 06:05PM
Location: Denmark, Odense C
Posts: 1968

Hi All

I salvaged a great deal of stepper motors, driver boards and power supplies from some machines, in hope of reusing it in building CNC machines.

As both the driver board and motor are proprietary products made for a specific customer, Oriental Motor does not release any documentation on these parts. There is also no documentation on their Vexta ICs, only through contract and disclosure deals.

I have the driver board C7576-004 with Vexta IC "EIC0202" and Vexta stepper motor 2-phase 1.8 degree/step DC 3A 1.5Ohm A5109-9412K

As I have the original power supply, motor and driver board I am sure that everything is connected correctly.

The input connector CN1 on the driver board has 5 opto ICs that are all the same type and facing the same way, this leads me to think they are all inputs. The original signal cable only used 5 wires, the connector has a common GND on the brown wire.

The only reaction I could get from the motor was to pulse the PC5 input on the orange wire, but the motor would turn jumpingly back and forth, vibrate heavily or just purr at me, depending on frequency.

I tried pulling either of the other inputs high to see if it was direction, all windings off or other of the inputs seen in this manual from page 21 on a newer driver from same company:

From what I understand from the timing charts, I only need direction set and a pulse train sent to the driver, a number of pulses for each step to take and frequency of pulses decides the speed.

Maybe there really is no way to test it in this crude way with just a signal generator or what action should I take from here?

Blackcurrant

Wed Apr 27 2016, 10:19AM

Registered Member #2989 Joined: Sun Jul 11 2010, 12:01AM
Location: UK
Posts: 94

On the 5 wires I would think there will be a common 0v and 4 control lines.

try a MM to see if you can see the 220ohm on the inputs

hen918

Wed Apr 27 2016, 05:07PM

Registered Member #11591 Joined: Wed Mar 20 2013, 08:20PM
Location: UK
Posts: 556

Is this a complete driver or just an amplifier? It is possible that the inputs just correspond with the outputs, and you would have to pulse them sequentially to get the motor to rotate.
Also, some drivers use one input for step forwards and one for step backwards rather than having one step input and a direction change.

Sulaiman

Wed Apr 27 2016, 06:58PM

Registered Member #162 Joined: Mon Feb 13 2006, 10:25AM
Location: United Kingdom
Posts: 3140

The opto's are TLP181BL , common type, current transfer ratio 200 to 600 %

I see no resistors in series with the inputs, so you need to have external current limiting resistors,
typical input current is 10 mA, c1.2 V across the led.

If you have been 'testing' the inputs there is a good chance that you have killed the leds,
they will still 'look' like a led looking at current vs voltage, but the opto may be dead.
A 'trick' is to short the output pins with a small (insulated) flat screwdriver blade,
this simulates the output transistor being 'turned on' by the led.
Opto's fail so frequently that at work we often blanket swap optos when we service equipment,
(cheaper than a warranty claim)

Most PLC etc. give 24 V signals so 2.2 kOhm 0.5 W is a common input series resistor.
(if very 'noisy' environment and/or long control cable runs,
I would connect a 1N4148 or similar in inverse parallel with the opto' input led)
(pcbs with many opto' inputs often use 0.25 W resistors, which slowly 'cook' the pcb or cause 'dry' joints)
Interface to a microcontroller as if it is a led.

I don't often do stepper drives but signals that come to mind are;

E-Stop = equivalent to Enable but physical normally closed switches in series for physical interlocks etc.
Enable = allow other signals to control outputs
Direction
Pulses (since you did not use series resistors operation would be 'sensitive'
Hi/Lo torque (current)
pulses/step (your driver pcb appears to have a separate jumper)

Blackcurrant

Wed Apr 27 2016, 09:16PM

Registered Member #2989 Joined: Sun Jul 11 2010, 12:01AM
Location: UK
Posts: 94

I bet the brown wire is the +ve supply for them
then you would switch the others to ground via a current limit resister to drive the leds in the opto
just like in the data sheet you linked to. doh!
on the plus side they would be easy to replace if dead

Mads Barnkob

Wed Apr 27 2016, 09:38PM

Registered Member #1403 Joined: Tue Mar 18 2008, 06:05PM
Location: Denmark, Odense C
Posts: 1968

You are right, I mistook the common for being GND, it is the common for all anodes of the 5 optos.

There are no resistors on the board and inputs measure 5MOhm to common pin.

These driver boards are meant to be used with a controller between it and the PLC, so PLC orders run to controller and controller sends a pulse train to driver.

I used a 4.5VDC wall-wart for testing the inputs, but it was reversed polarity due to the above. If I did damage the driver, luckily I got more :)

However interesting is that I got it to run, with heavy oscillations, but yet only from inputting pulses from signal generator on orange wire, PC5. So I am not so sure about there being a enable or e-stop, unless its a high signal, which makes no sense in terms of safety.

Sulaiman wrote ...

Pulses (since you did not use series resistors operation would be 'sensitive'

I first saw your replies and this after testing what is in the video.

Enjoy the torment

Blackcurrant

Wed Apr 27 2016, 11:04PM

Registered Member #2989 Joined: Sun Jul 11 2010, 12:01AM
Location: UK
Posts: 94

some ideas

CW pulse
CCW pulse
AWO output current off (motor spin free?) you could find this one easy or it may be the missing wire one from the header
Step angle switching
brake

or

Pulse sig
Direction
AWO
Step angle
Current cutback

Matthew

Wed Dec 20 2017, 08:00AM

Registered Member #61991 Joined: Sun Dec 10 2017, 07:21AM
Location:
Posts: 1

Hey Mads Barnkob i know this reply is a while after the post but i was wanting to know if u have worked out how to run this. if not i have access to the service manual and circuit diagrams of the machine that these parts came out of as i work with the machines for a living. if Im not mistaken the parts in the photos are from a butchery auto wrapper. I am willing to send you the documentation if you require it, just let me know if you need it and i can send it through to you

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