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parallel port to serial
« on: July 08, 2019, 02:03:59 PM »
Hi,
I recently bought a cnc engraver( 3 axis's ). It is a Chinese machine, Suda SD3025SXH.
It only has a serial port on the back of the machine and looks like it is only using 4 pins from the Serial Port.
I installed Mach3 on a PC and can get voltage on/off on pins 2,3 and 4.

I was thinking of using the parallel port  on the PC and connecting to the serial port on machine.
Anyone ever done this or am I wasting my time?
If possible - how do I go about figuring out the pin layout on machine?
Any advice appreciated.

Thanks,
Paul
Re: parallel port to serial
« Reply #1 on: July 08, 2019, 02:30:18 PM »
Hi,

Quote
I was thinking of using the parallel port  on the PC and connecting to the serial port on machine.

No, that will not work.

Machs parallel port is a lot more than just a db25 connector.  The parallel port driver takes numerical data, the
'trajectory', from Mach and converts that numerical data into simultaneous pulse streams, and can communicate those
pulse streams simultaneously over the db25 connector.

If you try to 'squeeze' the pulse streams through a serial connection all sense of simultaneity is lost.

Despite Machs parallel port being on the same PC as Mach (the Windows APP) it is separate and is a genuine motion
controller.

You can use Mach over a serial link, Mach transmits numeric data over the link to the controller and the controller
must generate the required pulse streams.

The distinction is.......motion controller in the PC (parallel port) verses external motion controller (within your machine control
box).

I can't find any info on your machine. Can you post some pics of the controller, take the top off so we can see inside?

Craig
My wife left with my best friend...
     and I miss him!
Re: parallel port to serial
« Reply #2 on: July 08, 2019, 03:42:42 PM »
Thanks for info.
Think this is the controller, not much info on it.
Apparently machine originally came with TypeEdit,
Supplier said they cant help - dont support machine any more.

Offline TPS

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Re: parallel port to serial
« Reply #3 on: July 09, 2019, 02:41:29 AM »
after a while of searching on the net, it Looks like the machine has a standalone Controller, and the Serial Interface is
used for file Transfer (GCode or HPGL). But found no Information about the used protocol.

if the supplier is not able to give some documentation, it will be very hard maybe impossible to figure this out.

anyway it will not be "compatible" to Mach3/4.

the only way i see is to use the existing stepper's and do a "retrofit" with new stepper Controllers and external Motion
controler. plus an other new controler for the spindle.
anything is possible, just try it.
if you find some mistakes, in my bad bavarian english,they are yours.
Re: parallel port to serial
« Reply #4 on: July 09, 2019, 03:54:18 AM »
I found a manual for it( or similar machine)
http://web.nchu.edu.tw/~daw/Manual/Metal_CNC_carving.pdf

Confusing part is the program they seem to use looks identical to Mach3.

Any suggestions on new stepper controllers and external motion controller and spindle controller, maybe this will be easiest option.

Could I try and just send G-code or HPGL) to machine and see if it does anything?
Or is there different versions (protocols) of the G-code - machine specific?
Read something on using hyperterminal to do this.
Thanks for info


Offline Tweakie.CNC

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Re: parallel port to serial
« Reply #5 on: July 09, 2019, 05:23:19 AM »
I am guessing that your machine has a 25 way 'D' type connector which will connect to a PC's LPT Parallel Port. In that case it should operate from Mach3 as the manual implies.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: parallel port to serial
« Reply #6 on: July 09, 2019, 07:18:10 AM »
Hi,
No only has a 9pin serial connector on the machine.

Offline Tweakie.CNC

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Re: parallel port to serial
« Reply #7 on: July 09, 2019, 07:44:27 AM »
That is a shame, so it looks like you are left with the option suggested by TPS of retrofitting a new controller and stepper drivers etc.

It's not too much of a job  (I did it a while back with a small milling machine where the manufacturers would not share information on their electronics because I was not and educational establishment) and all the required parts are readily available. It could be a fun educational project ?

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: parallel port to serial
« Reply #8 on: July 09, 2019, 08:20:23 AM »
Hi,

Quote
Confusing part is the program they seem to use looks identical to Mach3.

Hi, you are correct, they do picture a program page that looks remarkably like Mach3. It was a common technique
for Chinese manufacturers to take Mach3 and modify it for their machine and then sell it with their machine, a straight
out pirate derivative. Most of those manufacturers are gone. The screen shot in the manual you linked to is an example
of such a pirate derivative of Mach3.

If you can find a copy of it you may well get it to work but you will not be welcome on this forum....we don't support
pirated copies of Mach, either plain Mach3 or some derivative of it.

If you wish to get this machine going well do as TPS has suggested.

The first decision is Mach3 or Mach4. All development on Mach3 ceased six years ago, any bugs it has will stay that way.
It still has a huge fan base and is somewhat cheaper ($175 verses $200). Mach4 is the supported version, a much improved
and flexible solution that does all Mach3 did and more.

The second decision is external motion controller or parallel port. Both Mach3 and Mach4 have a parallel port option,
the Mach3 parallel port is free whereas the Mach4 parallel port called Darwin has a $25 license fee. Both parallel ports
require that you use Windows 7 or earlier and 32 bit OS. The parallel port despite its popularity (being cheap/free) is
not as stable and robust as a good external controller.

Well known, good quality controllers that have full manufacturers support include the Ethernet SmoothStepper (Warp9),
the UC300 (CNCDrive) or the 57CNC (PoKeys). These three all have both Mach3 AND Mach4 plugins. All three have fully developed
Mach3 plugins whereas The Ethernet SmoothStepper enjoys an edge in capability over the other two in Mach4. They range
in price from about $140 to $190.

There are other controllers like the CSMIO (CSLabs) at 600 Euro and the Hicon Integra (Vital Systems) at $600 for the base
model (more for various extra activated features); as you see they are very much more expensive.

There are a number of cheap to very cheap Chinese made controllers, seldom do they work well and none I know of support
all of Mach3s features and worse still you get zero support from the manufacturer. There is one Chinese manufacturer offering
what they claim is a Mach4 capable controller, XHC, it so buggy....avoid like the plague.

Craig


My wife left with my best friend...
     and I miss him!
Re: parallel port to serial
« Reply #9 on: July 09, 2019, 11:34:46 AM »
Hi, thanks for info.
Retrofitting looks like best option (probably only option ) and fun project to do.
Machine build does not look bad, apparently they used a German Spindle(water cooled), I generally try stay away from Chinese machines, for quality and support. You get better support from 50 year old machines than you do on brand new Chinese machines, but anyway I have the machine now.
 
The Ethernet SmoothStepper looks like the way to go, why not use mach4, not that much of a price difference.
Will this be able to control my spindle as well or should I just leave spindle alone?
What else will would I need to buy?
I assume a can keep the stepper motors already on the machine.
From what I can see the controller board connects to another board, think it is the board that drives the motors.
Will I need to replace this?

Sorry for stupid questions, not very clued up on electronic side.
Yet I have another project lined up - got a Deckel FP3 NC machine that I need to get up and running one day.
Hopefully that I wont have to retrofit, but who knows I might end up doing one day.