[notchtopper]

Hi all and thank you to all that look at this and try to help ahead of time. I have a Centroid CNC4 mill controller hooked up to a Shizuka knee mill with stepper motors. The machine has been working fine, great, I hadn't run the machine for a few weeks until now. So I turn the PC on and let it load up, open up the Centroid software and turn the Centroid controller on and nothing pops up. I press enter, nothing, I close the software and re-open it, nothing, I shut the control off and turn it back on nothing. The controller is getting power, I can hear the motors are powered up, but it seems like there is no signal between the controller and the PC, and I can't JOG the machine with the controller through the front panel of the control.

So I get new RS232 cables install them, nothing, so I spend $135.00 on a RS232 insulator and install that, nothing. Then I figure maybe it's the RS232 port that's gone bad on the PC, so I get another computer and install that, still nothing. I'm pulling my hair out and I really need this machine bad, I have a job with a deadline that is going to be a real big pain to do if even possible manually if I don't have this machine running. Any HELP would be greatly appreciated, like I said the machine has been running great, it's just been setting for a few weeks, now out of the blue this, PLEASE HELP, I'M FREAKIN OUT!!!

[johncarpenter]

So you are saying that the Centroid CNC menus come up but nothing will run? Just for grins sake, check to see if one of the jog/pause/etc push buttons are jammed down. They start to break apart inside with age and even though the outside shell has returned outward sometimes the inside part is jammed down. If you are getting no communications at all with the controller then that is something else. Probably easier to fix.

If everything goes belly up I have a complete CNC4 controller, and another CNC4 that has a bad power supply board but all else is ok. Or you can decide its time for a retrofit! (Excello Knee Mill Retrofit | Carpenters Woodworking and…..)

John C

[notchtopper]

Thank you for the reply and the offer, I might take you up on that, I appreciate it, I am happy with the controller and really don't want to have to do away with it.
It's not communicating with the controller, all the jog buttons seem to be unstuck, when you press the buttons there is a faint red light that lights up through the lens on the button, and I can press all the buttons and the light comes on and let go of the button and the light goes off, so that's not the issue, I don't think...

I don't know what to do, money is tight, I can't just have a tech come by and fix this for me, time is flying and I keep hoping that I get the answer so that I don't have to manually cut these parts.

What do you mean by "If your getting no communication with the controller then it's probably a easier fix."?

Thank you for the response, I appreciate all the help I can get.

[johncarpenter]

notchtopper
When you start your comm program does it boot up and communicate with the CNC4 controller? This is evidenced by after a while a menu comes up that says "Control Menu" and then has 9 options like 1. Run/Auto 2. Run/ Block etc etc etc. If is does, that means that at some point the dumb terminal talked to the CNC 4 control and got that menu.

Let me know what it is exactly doing. Most problems in the start up are communication problems.

Do you have the CNC4 manual? Have you done the diagnostic checks from the manual?

I once had a problem where the comms program would take up to 1/2 hour to establish communication with the CNC4 controller. So also try to start things up and leave them for 30 minutes and see if the control menu comes up. My problems were because the power supply for the 286xt computer that was running the dumb terminal software had a bad power supply giving low voltages.

If you are getting no comms at all then things like baud rate and handshaking may be messed up. Those are easy to fix. Settings are in the manual. If you don't have one I can scan the important parts and send them to you.

John C

[notchtopper]

Hi John,

Yes the menu comes up, but it comes up blank, it comes up without the run auto, run block, etc. etc.. and the controllers jog buttons don't jog the machine.

Yes I have the manual, and I did the diagnostics it says to do if you not getting communication, the only thing I haven't done is messed with the baud rate.
I don't know why I would need to make any adjustments to the baud rate, everything was working fine and no adjustments have been made so they still should be the same
as they were when the machine was working, right?

I will turn it on and wait and see what happens and check to see if the baud rate is set correctly.

Thank you John for your help,
Sam

[notchtopper]

John,

I checked the baud rate in the cencomm control menu and it's at the factory setting of 9600. This is the setting it has always been at and always worked with both computers I've had connected to it. So my question is, does this mean the baud rate is not an issue and if it still is how would I know what baud rate to set it at? Another question is why would I need to change the baud rate when I've never had a problem with it before?

I let the machine sit for 30 minutes or so and nothing happened, with the Control Menu opened, but none of the 9 options appeared.

Thank you again,
Sam

[johncarpenter]

Sam,

Please forgive me but I am still confused as to the sequence of events that your CNC4 goes through. Normally you boot the dumb terminal and it goes through its boot sequence and comes up in dos. You initiate the comms program and it starts. When the comms program is running there is a line at the bottom of the screen that says: F1-Load;F2-Save;F3-recv;F4-Send and on to F10 Exit Term. The existence of that bottom line means the comms program loaded and is running. After a while the The CNC4 controller and the comms program on the dumb terminal start to talk to each other. When that happens the line "Control Menu" appears in the middle of the screen. A 9 line menu appears below the first line that says "Control Menu". That menu means the CNC4 controller is up and running.

Do you have the line Control Menu in the middle of your screen? Do you have the 9 line menu under that "Control Menu" title line?

If you never get to the line "Control Menu then it it probably a comms problem. If you get the line "Control Menu" on your screen then the CNC4 Controller has an issue. Where does you start sequence quit?

John C

[johncarpenter]

Sam,

I am going to assume that you never get the line "Control Menu" in the middle of your screen and you never get the 9 line menu. So your comms are not not working.

When you tried a new computer for the dumb terminal did you get exactly the same results?

Are your new RS232 cables "straight through" ?

I assume that you checked all the RS232 connections. Did that include the RS232 on the computer board inside the controller box?

The manual suggests trying different handshaking options and see if it works.

And that's the end of the easy stuff. Next do a mechanical check of all board connections inside the controller. Wait 10 minutes after you turn the controller off before you open it. My systems is 80 volts and has big caps. Enough juice there to kill. Pull off and reattach all the ribbon connectors on the computer board and the power supply board. Take out the power supply board and look for leaking/bulging caps and any blasted components. Try running it again.

After that I have run out of ideas. At this point in my troubleshooting of my own system I bought a spare controller that was not working and did replacement swaps until the system ran. I still have all that stuff but to be honest I could (and did) retrofit my mill with modern Chinese electronics for less that the spare controller and boards are going to cost you.

Anyone else out there got any ideas?

John C

[notchtopper]

Hi John and thank you,
I get the control menu "cencomm" and the line at the bottom with the "F" functions, but I don't get the 9 line control menu in the middle of the screen "the one that has run auto, run immediate, edit program, and the rest of those functions.

When I put a different "not exactly new" computer in it did the same thing, and I've used both of these computers before for the dumb terminal and they both worked great.

As far as I know they are straight through RS232 cables.

I will have to look up handshaking and get a understanding of that, although I don't understand why handshaking or the baud rate would be a problem when none of those settings have been changed and everything was working fine, but I don't know a lot of things. Does the manual give you different options for handshaking or do I have to figure this out on my own? Forgive me I don't have it right in front of me at the time.

What do you mean by "Did you check the RS232 on the computer board inside the CNC4 controller box"?
You don't mean the RS232 port on the outside of the controller box, I take it you mean inside the controller and if so, no I have never opened the control up.

I will read up on handshaking and see what I can do, if there is anything else you can think of please let me know.

Thank you for all your help, I greatly appreciate it,
Sam

[notchtopper]

John,

I've been letting it set turned on for almost 90 minutes and I can now jog the machine, but the 9 menu is not populating the center of the cencomm control menu.

So I exited the comms "cencomm" program and re-opened it and still the same thing.

I feel a little bit better now that I can jog the machine, I don't know if I should or not, but at the moment I do even though the problem hasn't been resolved.

Why would the controller not jog the machine around and then all the sudden it does? Do the jog functions on the front of the controller run through the computer?

Thank you again,
Sam

[johncarpenter]

Sam, as far as I know all the front panel controls are handled by the CNC4 controller computer inside the control box. The other computer that runs Cencomm is just a communications device. So it sounds to me like you are still having comms problems. A possible scenario here is that the two computers keep trying to communicate but the connection is so bad that only a few bits are getting through to continue the startup sequence. You might try turning down the baud rate and see if that helps any. Any baud rate changes have to be done on both the CNC4 controller (Back panel dip switch) and on your dumb terminal computer whether it is the new one you tried or the old one alongside the CNC4 controller. Your new terminal computer was matched to the CNC4 controller parameters yes?

Please go over your controller box carefully. There are a lot of wire connections including grounds on the back. Make sure they are all tight, even the ones for the steppers and such. Go over all your RS232 cables and connectors. Any bent pins? I don't know what the thing you called an RS232 insulator is but it is not needed and if still in the loop may be adding to your problems. The controller back panel RS232 bulkhead connector goes to a cable inside the box that attaches with another connector at the CNC4 controller computer board inside the control box. If you can't fix the problem externally you should check the connections internal to the CNC4 box. CAREFUL! as I said before if you go inside the box wait for the life threatening voltage on the capacitors to dissipate. You go in through the front panel to see and access all the boards and connectors inside. If you want to remove a board (after removing board connectors from the front) you take the rear panel screws off and slide the board out.

Also go over the mill carefully, Any cut wires? Are any of the Axis up against a limit stop? It is very weird that a comms problem would come up suddenly. Mine let me know months in advance that trouble was coming. Are all the fans running properly? Any switches or anything loose on the front panel where their wires may be twisted behind the panel? 50% of all electrical problems can be discovered by a painstaking mechanical inspection. Thank god as I am a mechanical person only. That inspection should be looking for carbon traces for shorts or exploded components also. And leaking or bulging capacitors.

Good luck!

John C