[boyvox]

Still having problems with my Superior Electric Slo-Syn ss2000D6 drive.

I have the 5v from my usb connected to the Opto input, where it is supposed to be. I have the correct pins from my parallel wired to my Pulse/Step and Direction inputs.

My problem is that my motor only turns clockwise.

The manual states that the motor will turn clockwise when the Direction signal is High.

If I short the Direction input to ground or just unplug it the motor reverses direction and runs counterclockwise because the signal is no longer High and is now zero. This seems to indicate that the drive is not recognizing the Low state.

The manual says that the Direction input should be Low if it is <= 0.8Vdc and >= 0.0Vdc

I measured it when I pushed the keypad on the computer and it measured .08Vdc....which is on the low side of the range but still within parameters.

The manual says the the Direction input should be High if it is <= the OPTO and >= OPTO-1

My OPTO measured at 4.9 volts.
When I pressed the keypad to go in the High direction the DIR input measured 3.5 volts which is not >= OPTO-1 (4.9-1=3.9) So it seems to be out of spec.

The strange part is that the High signal is what seems to be working because the high signal is what moves the motor in the clockwise direction (which is what I am getting) but the High signal is the one that seems to be out of the acceptable parameters. The Low signal moves it counterclockwise and that is the direction I am not getting even though those readings are within spec.

Anyone else had problems with a motor only turning one way? Am I even barking up the right tree here? The pulse/step is working just fine but I don't understand why the direction is not working. The voltage readings and wiring scheme is identical on my Gecko drives and it works just fine but with these Superior Electric drives my Dir signal doesn't seem to be working. Any suggestions?

[ger21]

Can you increase the pulse width?

[boyvox]

I did try increasing the pulse width and nothing happened (using Mach2). The manual just gives specs for the Pulse as:

Max. Frequency=1 megahertz , Max Rise and Fall Times = 1 microsecond , Min. Pulse width = 0.4 microseconds

For "Other Signals" which would include the Step signal all it says is: Response Time <= 50 Microseconds

I only tried increasing the pulse width to 2,3,4,and 5 in Mach2 (nothing changed) but that is not much compared to the "<= 50 Microseconds" for "Other Signals". It is however much greater than the Pulse Max. of 1 microsecond.

I don't have an oscilloscope so I can't really measure anything in this realm.

[ger21]

In Mach2, try increasing the direction prechange. That's the one I meant to say. Try 5, 10, 15, 20, 25... and see if any of them help.

[boyvox]

Ok I tried changing the prechange and nothing happened. I think perhaps I may know what the problem is but I am not sure how to correct it.

The manual is very vague in it's explanation of which end to view the motor from to determine clockwise or counterclockwise rotation. I now believe that my motor is turning counterclockwise from the proper viewing direction ( it was a "duh" moment). I have re-measured the low signal and it it actually .8v on the direction input on the drive. Exactly on spec. The high signal is 3.5 which is not >=the OPTO-1(which in my case is 4.9v-1v=3.9v).That means that I either need to cut my Opto input to 4.5v so that the 3.5v Hi Dir signal will be exactly 1v less than the Opto or I could somehow boost the 3.5V direction signal by at least .4v. It seems like it would be easiest to cut my opto signal down to 4.5 but as I am not versed in basic electronics what-so-ever...I don't know how to do that. Should it put a resistor on my 4.9v wire out of the USB to lower it to 4.5? Or an attenuator? Or some other type of magical widget! Looks like I need some basic electronics boot camp!!

[H500]

.8v is the MAX voltage allowable for a low. Since you mentioned that grounding the pin will reverse the direction, it means that you're not low enough. What is your circuit?

[boyvox]

I think I was wrong about that. It seemed like it did that yesterday but today I couldn't replicate it so I don't know what I was actually doing then. Today I found that if I remove the parallel port step wire from the Dir input on my drive that the Dir input on the drive itself reads at 4.3V and the motor reverses and turns in the direction that I want to achieve when it's hooked up to the computer. So I am figuring that the .8V Low is actually working fine and it's the 3.5V High that is not working because it is the 3.5V which is .4V below the minimum (4.9V OPTO-1V=3.9V). Does it make sense that the drive would be in the High state until I plug it into the computer and it then thinks that it's in the low state because both the signals from my computer are under the minimum requirement for a High signal?

[H500]

That sounds plausible. You will need some sort of level converting circuit, or if your circuit is able to run from a lower supply voltage, you could wire a diode in the power to lower the voltage by about .7v.

[boyvox]

Yeah my circuit specs are : 4.5-6VDC 20mA per signal used. I don't understand what the "per signal used" means. So it sounds like the diode would be a possible solution for lowering the voltage. How about an alternate power supply? There are lots of 4.5VDC wall warts available but they often have 300 or 600 mA ratings. I am a little confused about that specification on them (again...complete lack of electronics knowledge). Does that mean that they output 600mA or does that just mean that that is the maximum current that can transmit through them? I don't like messing with electricity much so I am not interested in messing with any power supplies (even though its 4.5V) unless I understand what I am doing. I do really want to try running it at the 4.5V to see if that changes my motor direction, so I need an easy, safe way of getting 4.5V to the OPTO input. Wall-wart seems like that would be easy but I don't understand what the 600mA rating means or what my Drive's circuit specification of 20mA "per signal used" means.

[H500]

It probably mean each signal pin need 20ma. The supply rating is the max current that it can supply. A wall wart won't do, unless you get one that's regulated. With an unreg one, the actual voltage changes with the loading.

Without info on what your circuit is, it's difficult to give you any meaningful solution. I can only guess at what you are trying to do.

[boyvox]

Ok well this is where I am too deep in the water I guess. What do you mean "info on what your circuit its" ? I am using a Superior Electric Slo-Syn SS2000D6 Drive unit with a Superior Electric 3.2V 5A stepper motor. I'm trying to hook it up to an old Thermwood CNC I have. I do not have schematics for the Drive.

I simply want to use Mach 2 and wire it directly from the pins on the parallel port to the inputs on the drive just to get it to run back and forth a bit so I can make a final decision about my motors and these drives with this machine. I don't have a breakout board for this yet so it's just the 5v from the computer straight into the Drive as well as the Step/Pulse and Dir from the parallel wired right into the inputs on the Drive. The motor's power supply is integrated into the drive so I just need to get signals that agree with it's logic requirements and it is a self contained unit.

I have some Gecko G201's that I could run them off right from the parallel and the 5v usb power, but I am using them on another machine.

I don't know if that is the info you are looking for but it's a simple explanation of what I am trying to do.

I just see that my 4.9V power supply and my 3.5V High Dir Signal do not fill the requirements of the Drive's logic setup, so I can either choose to somehow boost my High Direction Signal from the computer or lower the 4.9V OPTO input and then the signals will be within spec.

Here are the logic requirments on the drive:

Direction Input
Voltage:
Low if it is <= 0.8Vdc and >= 0.0Vdc
High if it is <= the OPTO and >= OPTO-1 volt

Pulse/Step Input
Voltage:
Low if it is <= 0.8Vdc and >= 0.0Vdc
High if it is <= the OPTO and >= OPTO-1 volt


OPTO
Voltage: 4.5-6VDC
Current: 20mA per signal used

TIMING REQUIREMENTS
PULSE: Max. Frequency=1 megahertz , Max Rise and Fall Times = 1 microsecond , Min. Pulse width = 0.4 microseconds

Dir: response Time <=50 microseconds


That is all the information I have to work with. The drive and power supply for the motor is all contained within the box, no diagram available. I just want to hook the Pulse and Dir singals from my PC parallel port in and get the correct power to the OPTO input and I should be able to test out my motor.

[H500]

Detail on your opto board would be useful. From the look of things, your opto board need more current than a PC port is able to supply. The no-brainer approach is to "find" an add-on parallel port (or an older computer) that happens to supply more output. This is a trial and error process and not garanteed to succeed.

Lowering your opto supply voltage might work, but it really depends on the circuit. Since it's easy to do, you could just try adding a 1 amp or higer Shottky diode in series and see if it works.

The "proper" solution is to build a simple buffer board. It would take no time to test it out on a breadboard.

If all you want to do is test out your motor, why not just connect it to your other gecko drive? (assuming that its a 4 wire bipolar motor)

[boyvox]

I just picked up a PCI Card at the store for 25 bucks. It puts out 5V at the pins instead of 3.5 and that works just fine....motors turn in both directions no problem. So simple There's a few ticks here and there that might be missed steps so I'll have to investigate further. I like the motors and the drives have selectable steps from 200 to 50000 steps and that all seems to work fine. Dip switches for up to 7 amps.

Thanks for your help and for being a sounding board. If I can't figure out what's causing the possible missed steps I'll be back, but for now thank you very much.