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Author Topic: Breakout Boards  (Read 22611 times)

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Offline comet

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Re: Breakout Boards
« Reply #20 on: November 18, 2007, 12:06:32 PM »
Jeff,
  yes those opto22's are great I use them whenever I need to switch AC from 18-230 volt.
Plus there forever coming up on ebay for next to nothing!
  I supose with my builds I take a "minimalist" view,and I never use an expensive controller computer.
as long as its 2gig and costs less than £100 then its a winner.
  Tony

Offline Chaoticone

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Re: Breakout Boards
« Reply #21 on: November 18, 2007, 12:09:06 PM »
Good job Jeff.

Overloaded, look at this link.  http://www.rogersmachine.net/PCIport.html   

Also, tiger direct, new egg, and others will have dual cards. That is what I use in conjunction with BOBs

Brett

« Last Edit: November 18, 2007, 12:11:07 PM by Chaoticone »
;D If you could see the things I have in my head, you would be laughing too. ;D

My guard dog is not what you need to worry about!
Re: Breakout Boards
« Reply #22 on: November 18, 2007, 03:24:03 PM »
EXCELLENT !
 MUCH good input.
Jeff, I can see where isolation may be essential as you say in some cases.
I'll dig a little deeper before I place an order.
The common transformer set-up does seem strange, hmmm ? ?
Thanks for your input.

Tony, good tip on the shield grounding, I'll do all I can to control the noise.

Brett, thanks for the link. Tiger has a dual for $22. If I were to use 1 or 2 MPG's on my project, the added IO would be necessary, would it not ?
They have a single for $14. Cheaper than I expected. Description says that they are 3 times faster than the motherboard port. I take that to be a plus as well.

Much thanks to all
Re: Breakout Boards
« Reply #23 on: November 18, 2007, 03:32:43 PM »
This just in:
Maybe I should think twice before ordering a PCI board from Tiger.
Here are some reviews from their site. Anyone had this sort of trouble with PCI's ?
Rogers Machine may be the way to go.


REVIEW BY: jwines1 Reviewed  Sep 21, 2007 
Would not work on XP tried every driver on the disk, was not Cables Unlimited card, nothing like the picture shown, waste of money

 
REVIEW BY: Plain Reviewed  Sep 07, 2007 
This port's drivers simply would not install in a WindowsXP box. After hours of trying I gave up. An email to the manufacturer resulted in a boiler plate response. When I replied to the email telling them it still didn't work, I got no response.

 
REVIEW BY: Bigtexan Reviewed  Apr 04, 2007 
I'm using XP and all I had to do was plug the card in and go. It took care of everything with no problems.

 
REVIEW BY: tbe6 Reviewed  Mar 01, 2007 
xp would not accept it. sent me an old board,9835 rev c. after reading install directions(had better in my dos days)i gave up and went looking for a real board.


Offline comet

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Re: Breakout Boards
« Reply #24 on: November 18, 2007, 03:40:16 PM »
hi,
forwarned is forarmed they say !
if The main chip says Netmoss on it it should work fine
    Tony
Re: Breakout Boards
« Reply #25 on: March 20, 2008, 07:30:50 PM »
Anyone have experience with this: Opto-22 SSRs turning on/off & powering a coolant pump?

I'm about to hook up the flood coolant motor so it will turn on/off via Mach 3  -- it's 110vac @ 1amp (although start up load is what 3 amps?). 

I plan to use the Optp-22 and I have SSRs that "appear" to be far higher rated an that.  But there's something about hooking up a motor to SSRs that I don't quite understand...

But I live in fear --> A couple of years ago I burned up a Hydrodraulic Valve Solenoid and an Opto-22 (Ethernet Snap) SSR (back plane was OK because it's "opto-isolated!). In that application the SSR also appeared to be rated for the load -- obviously I'm not an electronics expert, as such I'm concerned that I'll burn up something -- like the motor and/or SSR. I'm told the duty cycle/load of a solenoid is a different beast than a motor.  But that doesn't resolve my concern.  As such the coolant motor is plugged into a wall socket and light switch...

Suggestions?  Is the best solution to put a mechnical relay in as well -- isolated the Opto-22 isolator as it were?  If so, then I'll pop in a 110v relay.  But hey if the SSR can handle it, that one less thing to wire in.

I realize that any suggest is "use at your own risk".

--Scott (fastest e-stop button user in the world).

--Scott
Re: Breakout Boards
« Reply #26 on: March 21, 2008, 01:17:44 AM »
I don't have any experience with the Optp but, putting in a relay sure is a "cheap insurance policy".  If you blow a relay, it sure is easy to pop it out of it's socket and replace.  Would it be that easy to recover if you blow your Optp?

Just my $.02

Sid
Re: Breakout Boards
« Reply #27 on: March 21, 2008, 02:38:59 AM »
Oh that's worth a lot more than $.02!   ;D 
--Scott

Offline jimpinder

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Re: Breakout Boards
« Reply #28 on: March 21, 2008, 06:00:43 AM »
I am using a breakout board - from Routout CNC (in the UK) - I don't think he makes them - just markets them. It is a "dead" board and just provides any easy way to connect to the computer - and a good strong terminal strip in my "box of tricks".

The connections to the stepper driver boards (also from Routout) are direct from the breakout board. Wirng is so short that no shielding is necessary. I find outputs, for spindle motor, and coolant are best done via relays. Mine are 5v driven direct from the breakout board via a Darlington array chip - all four relays from the one chip. The relays are then connected to the Omron spindle drive inverter, and to the fluid pump. If you need a bigger relay - then keep the small relay - and just get it to drive the bigger relay - don't mess about with different voltages etc.

All my limit and home switches (see "laser gun sight") are wired at 5v - and linked directly back to the breakout board.

So - do you need opto isolation - then only trouble is - if things won't work it is a devil of a job finding where the fault is if you are  trying to check voltages and everything through several "stages" - and the more complex you make it, the more likelyhood you have to make a wrong connection.

I have everything going into my control box on DIN plug connectors, or external connector strips. If anything goes wrong, I can unplug the affected bit and test it - in isolation to the control box. - then open the box and quickly test from the computer to the connector using the breakout board - which is easily accesible. I also have direct access to what the computer is putting out.

In my opinion - and I am aimed at the amateur/semi professional end of the scale - keep everything simple. Try and plan everything to use just one voltage at "ground" level - which avoids any likelyhood of feeding something nasty back to the computer. Isolate simple switching via relays - which guarantee a clean voltage seperation. I must admit that, with drives you are in the hands of the manufacturer, maybe so far I have been lucky. I use seperate boards for each axis, I am unlikely to blow all three at once - and replacing one board is a simple and relatively cheap job. I have just blown one on the Xaxis forcing the motor to push a tool against the workpiece - quite by accident, whilst I was testing something else - the replacement should arrive today.

As for Stepmaster boards - I used them, but found their marketing etc a bit convoluted and long winded- they seemed to work well enough though.
I blew them connecting the power supply the wrong way round one day ( a thing I  have now protected against by using a big diode bridge on the input). I use Routout bacause they offer good delivery times here in the UK.







« Last Edit: March 21, 2008, 06:03:34 AM by jimpinder »
Not me driving the engine - I'm better looking.

Offline Jeff_Birt

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Re: Breakout Boards
« Reply #29 on: March 21, 2008, 10:43:10 AM »
You need to be sure that you are selecting the correct SSR for the job and providing it with a proper heat sink. I have yet to kill an Opto-22 SSR. Check out: http://www.opto22.com/documents/0859_Solid_State_Relays_data_sheet.pdf, look at page 14 it gives model # recommendations for various sizes of electrical motors. Also triple check what your motor is really drawing, 1 amp at 120V is around 1/10 HP (maybe) are you sure your pump isn't bigger than that?

Quote
Would it be that easy to recover if you blow your Optp?
yep, they plug right in/out, no worries and are MUCH more reliable than mechanical relays. You can use the smaller (rack mount) Opto-22 SSRs to drive large contactors/relays etc. This is useful as it provides both the optical isolation of the SSR and the current capability of the relay.

Quote
Wirng is so short that no shielding is necessary.....if things won't work it is a devil of a job finding where the fault is if you are  trying to check voltages and everything through several "stages"....Try and plan everything to use just one voltage at "ground" level - which avoids any likelyhood of feeding something nasty back to the computer.

OK, 'grounding'...'(earth)ground IS NOT equal to DC common. They do not mean the same thing, unfortunately we all throw around the term 'ground' very loosely. 'Ground' is this context refers to 'Earth Ground' which is a safety device. The incoming mains voltage is referenced to ground (through the 'ground' rod(s)) and so is your equipment. This provides a path of least resistance to shunt the voltage away from important things like people in case something goes wrong. 'Ground' SHOULD NEVER carry any current, it IS NOT a common return path for all circuits. That is the job of DC common, and your system may have more than one DC common which is not a big deal.

The problem is that folks think 'ground' is this universal reference for EVERYTHING in a system and try to measure voltage to it from any given point, which is wrong. Think of it this way, if I were to nail three pieces of wood together at odd angles and ask you to measure their length how would you do it? Would you pick the bottom of the closet piece of wood and measure from there to every other piece? Or, from the floor (ground) to each piece? Nope, because that would not tell you a thing. You would run your measuring tape from end to end on each piece of wood (so your reference is the beginning of each piece of wood and you are measuring from that reference to the end of the wood to find its length.) Measuring voltages is the same idea, you are measuring from a reference point (common) to some other point in the same circuit (same piece of wood).
Happy machining , Jeff Birt