Plz help me interface IM483 driver to parallel port

[dondeaida]

Hi everyone, I'm new to cnczone as well as to CNC in general. Plz be EZ on this noob....

I got a couple of IMS IM483 drivers from ebay (8 pin P1 version, not 34 pin P1 version).
Has anyone succesfully wire this driver to breakout board for Mach3 (or similar software) use?

Attached ScreenHunter_042.jpg file shows IM483 driver has 8 P1 pins, among them is +5v "opto supply" (P1:4), but NO GROUND PIN for opto supply.
How should I GROUND the +5v opto?

To the driver side ground maybe... but the manual has a line saying (Plz open Attached ScreenHunter_043.jpg file) --->

"In order to maintain isolation, the optocouplers must be powered by an external power supply connected to P1:4, with the opto supply ground connected to the ground of the input control circuitry..."

This seems to preclude grounding +5v opto to driver side (motor side) ground pin (P2:3 for IM483)

Attached ScreenHunter_041.jpg, Attached ScreenHunter_044.jpg and Attached ScreenHunter_045.jpg are 3 signal input methods (interface methods) IM483 manual mentions (Switch Interface, Open Collector Interface and TTL Interface) however, the manual does not at all discuss computer-interfacing IM483 (Not a word of "computer", "parallel port" etc..)


manual is at ---> http://www.imshome.com/Product%20Manual%20PDF/im483.pdf
data **** ---> http://www.imshome.com/Product%20Datasheets/im483.pdf

Has anyone succesfully wire this driver to breakout board for Mach3 (or similar software) use?
I would so much appreciate your help.

Thank you for your time...

[Stepper Monkey]

Don't ground it to the motor supply side!

I haven't taken a good look yet at the specs, but I would check to see if the inputs themselves (step, dir, etc) aren't designed for sinking outputs.

I would also like to see what the electronics gurus on here would suggest for hooking this up simply to a Mach interface, I am curious to see the best way accomplish this.

[pminmo]

This is a pretty common optocoupler based drive. If your PC has usb capability you can possible steal 5V by cuttin off the connector on the non pc end and using the 5V and common wires. You can use a small 5V dc "wall wart" supply for an isolated 5V. Seach the threads here on the zone for wiring gecko drives, your's technique wise are virtually the same.

[fyffe555]

Originally Posted by pminmo This is a pretty common optocoupler based drive. If your PC has usb capability you can possible steal 5V by cuttin off the connector on the non pc end and using the 5V and common wires. You can use a small 5V dc "wall wart" supply for an isolated 5V. Seach the threads here on the zone for wiring gecko drives, your's technique wise are virtually the same.

Phil's spot on as usual. I use exactly as he suggested with IM483 8P and 34 drives..

As Stepper monkey suggests the step dir and enable sink the opto 5v to earth through the interface / breakout board.

[Stepper Monkey]

I think the question he had was not so much what to use to feed the +5v in with, but where to place the black wire from the wall wart. I understand where his confusion comes in as this is really quite counter-intuitive to non-electronics folk.
I understand how this works with some types of breakout board, but I do not know enough of electronics to feel safe suggesting a catch-all solution for different types of interface - I am unfamiliar with the fundamental differences in electrical behavior between directly interfacing with the port vs. outputs from another opto stage, and don't want to suggest something incorrect.

Perhaps one of you guys could indulge us with a bit of an education on what the signal is actually doing here to help visualize, or perhaps just a recommended way of doing it most simply? I'd be interested in this, too.

[dondeaida]

Thank you Stepper Monkey, pminmo and fyffe555.

To better articulate my need, I think my question comes down to this ---> Where do I connect the ground wire(black wire) of the +5v opto voltage supply? (I am of course refering to the seperate/independant +5v supply to the optoisolation circuit of the drive, NOT the main power suppy)

I looked up Gecko drive manuals as pminmo and fyffe555 instructed and found that Gecko drive is identical to IM483 drive in that ---> Neither drives have seperate ground pin for the +5v opto voltage supply (I am again refering to the seperate/independant +5v supply to the optoisolation circuit, NOT the main power suppy. Both Gecko and IM483 of course DO have ground pin for main power supply)

As to the +5v power source, it could be a 5V dc "wall wart" supply or as pminmo instructed, 5v supply coming out of USB port or even the red wire (+5v) coming directly out of any PC power supply (right? In fact I am powering up my LCD monitor directly from PC power supply, in this case 12v yellow wire)

Now, back to my main question ---> where do I connect the "ground wire" of the 5v power source?





For a 5V dc "wall wart" supply way, connect +5v wire to +5v opto supply pin of IM483 drive (of course) and then connect the ground wire to breakout board's ground pin? If so, may I use one of those "cheap" breakout boards that offer no isolation? Wouldn't those cheap breakout boards damage the parallel port (printer port) of the computer?

Please allow me to skip the USB way, since I am not familiar to which pins of USB port are +5v and ground pins.

For PC power supply's red wire way (this would be my choice over "wall wart" power supply) connect red wire to +5v opto supply pin of IM483 drive (of course) and then connect the black (ground wire) coming out of PC power supply to breakout board's ground pin? (Is this right?)

Someone suggested that regardless of the 5v power source, I need to first connect (5v source's) ground wire to driver's ground pin for the main power supply (as you remember, the driver does not have seperate ground pin for +5v opto power supply but of course do have ground pin for the main power supply) and then get an extra wire and connect this wire in between driver's ground pin for the main power supply and the breakout board's ground pin... (Will this work..?)

Again, will "cheap" breakout boards work in any of these ways?





Hope I have articulated well enough what help I am seeking.
I would again appreciate your expert advice. Thank you for your time and have a great day!

[Stepper Monkey]

You do need a more expensive opto breakout to safely run a driver like a Xylotex as they have no couplers built in. Hooking one up directly to your printer port through a simple breakout leaves no isolation at all from possible shorts.

If you have inputs on the drive that are are optocoupled as you do, then there is no danger of cooking the printer port. Where the opto stage is located (whether on the driver or the breakout) isn't relevant as long as it is there inline somewhere to stop a flood of angry ohmites (the small creatures who live in your wires) before they hit your computer port.

Again, this is not my area of expertise, but I believe if you ground the motor side to the printer ports ground on the breakout board you have just completely defeated the purpose of isolating them in the first place.
This definitely needs someone to give us a primer on theory here.

I may be dead wrong here, but with no other guidance I would hazard to guess that you might need to use a switching transistor, or maybe a resistor between each output and ground to pull down signal unless this is built-in somehow already. Depending on how the port ground works perhaps a simple low-active setting in Mach will make a direct port connection work with +5v to the driver and ground to the port ground. Without expert guidance I would have to start fiddling with one to figure it out. Sorry I can't help more. I wish more of the EE's would actually read the electronics sub! Perhaps also ask the question on the Stepper Drive sub to find someone to answer.

How does a sinking output work directly from a printer port vs. an opto output from an isolated breakout? Are they wired exactly the same????

[pminmo]

Originally Posted by Stepper Monkey You do need a more expensive opto breakout to safely run a driver like a Xylotex as they have no couplers built in.

That is just dead wrong! There are a gazilion periperials and equipment running parallel that have no opto isolation. In a properly wired system, you can run just perfectly fine. Opto's become more important when there are heavy currents, high voltage, and a electrical subsystem that is iffy like in many factories. If also is an equipment protection for those who wire systems who are not sure what they are doing, or don't have the resources to make a few simple checks. It's all about current paths, and physical wiring layout to make sure the heavy current paths are routed properly.

[pminmo]

dondeaida,
The wall wart is used to power the input side of the drive. It's negative needs to be connected to the lpt gnd pin 18-25. Positive side to the 5V of the drives. The PC output pin is essentially a switch to pin 18-25 when it is low, conducting current through the opto emitter. So the current path is wall wart 5V, opto emitter, PC output pin, PC common/wall wart negative.

[fyffe555]

To add to Phils post, the isolation occurs inside the drive. The pc port(s) connect to the drive, usually via a breakout board but not necessarily requires, the 5v coming from the pc or a seperate 5v supply needs to be grounded to the pc ports ground. The opto's isolate the signals inside the drive from the rest of the drive. The motor supply is not connected to the pc at any point, the motor supply is regulated to power the internals of the drive as well as provide the motor power. Again, there should be no connection of the motor supply to the pc at all.