Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: panaceabeachbum on August 31, 2008, 07:19:18 PM
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I have three machines between 2 and 15 HP all running VFD and three phase spindle motors , all have the vfd mounted in the same cabinet with my breakout boards relays , amplifiers etc with no problems.
I am finaly finished with my big MHP 30hp lathe (THANKS HOOD) , the last thing to do was wire the VFD to the breakout board so mach can control speed direction etc. The VFD on this one is mounted on the wall aprox 6 feet from the machine and everything has been working perfectly before hooking up the control wire . Walk over push the start/stop buttons etc no interference.
I have run a sheilded cable from the VFD to the breakout board consisting of one wire from the analog out on my breakout board , two wires +- from the vfd power supply to the breakout board and three wires from the vfd for direction , common and fw/rv . Both ends of the sheild are grounded , tryed it both grounded and ungrounded.
Now the instant I switch the spindle on with either m3 or m4 it spins breifly and I get an estop and the watchdog triggered message. In General config the debounce and index (?) settings were set at 200 for the top one and 4 for the lower one. At those settings the spindle will spin up for almost 10 seconds before going into estop . I have adjusted the numbers up and down with out any better results.
If I disable the watchdog in gen config I can power up the spindle but everything on screen freezes , cant move the mouse , hae to hit the physical estop and once the spindle winds down everything is fine , While the spindle is running I can walk over and turn the vfd off by using the stop button on its control panel , it stops as it should but Mach is still frozen until I hit estop .
Any thoughts on how to solve this problem greatly appreciated, should I possibly not be using the 10v power supply in the VFD for the analog output on my breakout board? on all the others I am using a seperate power supply , this 30 hp vfd had a power supply built in .
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Best to just have the shielding grounded at the control end I think.
Try setting the debounce to 2,000 and see if it helps but really thats not a great idea as it slows all responses down.
Do you have the motor wires shielded? Maybe that is the source of the noise.
Hood
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the motor wires are not sheilded but they never get anywhere near the breakout boards , any wiring or the cabinet that everything is in . They also didnt seem to cause any problems while i was running it this week turning it on manualy with the key pad. i will try detaching the cable sheild from the ground in the VFD and play with a much higher value for the debounce to see if that helps
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OK didnt realise it was working from the VFD previously, just thought it was possibly the manufactured 3 phase from the VFD that may have been the issue. Dont know a great deal about grounding but from what I gather its best to have only one end grounded and also to have all of your grounds connected to one single point.
Hood
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It's generally not a good idea to ground a shield at both ends. That encourage the shield to become a conductor, which is *really* not what you want. I would connect the shield only at the VFD end, since the VFD is providing the power for the signals. What BOB are you using, and how is it connected?
Regards,
Ray L.
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Thanks Hood , I just set the debounce at 2000 and 3000 with no luck , also just have the control cable grounded on one end . No luck yet . I am going to pull the control wire thru metal conduit instead of plastic in the morning and see if that helps.
The other thing that might be causing a problem is the cable I am using for the control wire has 4 extra wire that are unused , I just folded them back and tie wrapped them to the cable on each end. Is it possible these are acting as an antenna of sorts picking up stray RF ?
This is the first one I have done where the VFD is outside the main cabinet , all the others are just a foot or so from my breakout board and are all bonded to the same big grounded mounting plate, I wonder if a big bonding strap between the VFD and the body of the machine might help. The machine , the VFD , Rotary Phase converter, motor and Delta to Wye transformer are all well grounded
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"Is it possible these are acting as an antenna of sorts picking up stray RF ?" - Not really.
Is the *only* difference between the configuration that works and the one that doesn't that you've added the control cable from the VFD to the electronics enclosure?
Regards,
Ray L.
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Hi Ray , I have tried it with the sheild grounded at both ends and just one end , at the VFD and in the main cabinet, each in turn , no change.
I am using the C11 board from CNC4PC , same BOB I am using on 3 other machines running VFD .
I have to 10v power supply from the VFD attached to the external power supply input for the analog out on the BOB , The analog out signal 0-10v is attached to the analog input on the VFD .
There are two dc relays on the c11 BOB , both with NO contacts and a common in , one is triggered by pin 1 the other by pin 16 . The VFD has a 24v power supply for the inputs that choose direction , in the VFD I have the switch set to source inputs and the + from the 24v power supply run to the common in term on the relays and one wire each to the two terminals in the VFD for forward and reverse . I have set the switch to sink and attached the - to the relays, same interference.
M3 is set to output 1, output one is set to trigger pin one , When M3 is called out the relay at pin one is energized and completes the circuit to the VFD to turn clockwise (forward with my rear turret lathe). Which it does until the watchdog trig thing puts the machine in estop. Reverse is wired similarly to the relay on pin 16 , m4= output2. output2=pin 16 , m4 callout energises the relay at 16 and the spindle turns anti-clockwise until the watch dog triggers estop .
I am pretty sure the BOB to VFD wiring is correct , I have been using the same setup (smaller vfd) on three other machines for quite a while with no problems. I am sure I am just overlooking something simple
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Yes thats the only difference , worked perfectly before the control wire
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Do you have any ceramic or other non-polarized caps around? Might try connecting one to each signal lead at the BOB and to signal ground.
Kristin
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What revision is your C11 board? It should be screened on to the board somewhere.
Regards,
Ray L.
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Also, how do you have things grounded? It's important to have a single, common ground point that everything connects directly to. You don't want to have grounds daisy chained. Each device should have its own ground wire, which runs directly to the single common ground point, ideally a big lug on the metal chassis. Doing otherwise can create all kinds of flaky, mysterious problems.
Regards,
Ray L.
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Ill look this morning for the revision , everything is properly grounded to a buss bar in the cabinet which is attached to a couple of ground rods via a big bonding strap. Everything else related to this machine is also grounded to the same ground rods, rotary conv , transformer , vfd
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RT,
You mentioned an external E-Stop. I recently set up a C11 to a VFD and had the E-Stop on pin 15. There is definitely a problem with 15.
Within 10 or so seconds, I would get "External E-Stop Requested". Moved to pin 12 and THAT problem went away....but there were others. Went to a PMDX 122 & 106 with much Much MUCH better results.
RC
Here is a link to that story :http://www.machsupport.com/forum/index.php/topic,7679.0.html
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I am not sure its the VFD thats the probelm . I rebooted the computer, turned on the power supply to the BOB , and I am getting the same watchdog trigger message as soon as I click the spindle button . This is with the VFD off and before the big rotary phase converter is powered up.
If I open gen config and turn off the watchdog as soon as I press the spindle button on screen the program goes into estop.
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The c11 board is version 5.4 .
I would suspect my wiring scheme but its the exact same on the other machines .
I havent found anything that can be hooked to pin 15 without causing issues except the spindle encoder so I dont use it
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I am def starting to think it might be software . I have the pulley setting 1 to 1 , limit 1700 rpm . As long as I call out m3 s800 or less the spindle motor spools up just fine but as soon as I try to jog , callout any moves in the mdi Line or pretty much do anything else on screen I get the watchdog triggered message. When the m3 command has been entered the mouse moves very slugishly on screen even when the VFD and rotary phase converter are powered down and the watchdog trig message pops up as soon as I type anything in the mdi line.
The machine has been working fine with the rotary conv running , spindle running etc all week , only since I have unchecked the Disable spindle relays box in spindle setup has the problem developed.
I can check the disable spindle dialog box and go back to using the keypad to turn the spindle on and off and everything seems to work fine, even with the conrol wire still in place.
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You using the latest versions for development testing?
Hood
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yep, I will load an older version when I get back
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that may well be your problem as it seems even the latest version is still hanging on some prcesses.
Hood
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Well no luck, I installed the locked down version , reloaded my tool change macro and all the setup files . Same problem . With the VFD off , no possibility of stray RF its still doing the same thing .
When I click the spindle button or callout m3 the driver watchdog message will trigger within 10 seconds everytime.
The machine runs fine and everything works as it should when I go over and manualy turn the spindle on with the keypad , mach runs fine and the machine makes perfect parts but the minute an m3 or m4 command is entered the watchdog message pops up and the software goes into estop.
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So, if I'm understanding this correctly, the only thing the M3 is doing is setting one of the PP outputs to command the motor on, but that signal is basically going nowhere, right? That sounds like a flaky BOB.... I did have that kind of problem with my (really old) Rev 2.0 C11 board, but since getting a Rev 7, no problems at all. I wonder what the differences are between my Rev 7.0 and your rev 5.4?
Regards,
Ray L.
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no its turning the motor on and off just like its supposed to . I have tested it with indicator lights and with the VFD and it turns everything on and off properly . The problem is when it does I get the watchdog message and the program goes into estop even when the VFD is not hooked up .
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Richard, what are you speeds set to in config., spindle pulley?
Brett
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its set 1 to 1 , 1750 rpm
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Have you talked to Arturo? I have one of his BOBs in my mill and couldn't get the analog output for the VFD to work. He sent me a later revision but I haven't messed with it yet as the logic for it was opposite, there have been later revisions since the second, and I haven't had time to rewire. I just use 2 outputs for now for forward, reverse and both or neither is stop. I just go to the VFD and adjust the speed if needed.
Brett
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I am going to drop him a line in a few minutes but to be honest his BOB is doing everything correctly , when i call out m3 it closes the contacts on the mechanical relay just like its supposed to and it properly adjust the analog out put thru the full range from 0-10volts depending on the s value so I really dont think its a problem with the board. I have 2 other identical boards purchased at the same time wired just the same that are working perfectly. The only diff is both those machines are running much earlier versions of mach and teco VFD , this one has a 30hp automation direct VFD . I was also running a much later version of mach.
When I installed the earlier version of mach 2.** after the later version 3**is there anything special I need to do to uninstall the newer version ? or is it ok to install as if I am upgrading
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Nothing special to do to load an earlier version of Mach. Does the BOB have a pin for the common form the drive and the analog out?
Sent you a PM.
Brett
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I am going to drop him a line in a few minutes but to be honest his BOB is doing everything correctly , when i call out m3 it closes the contacts on the mechanical relay just like its supposed to and it properly adjust the analog out put thru the full range from 0-10volts depending on the s value so I really dont think its a problem with the board. I have 2 other identical boards purchased at the same time wired just the same that are working perfectly. The only diff is both those machines are running much earlier versions of mach and teco VFD , this one has a 30hp automation direct VFD . I was also running a much later version of mach.
When I installed the earlier version of mach 2.** after the later version 3**is there anything special I need to do to uninstall the newer version ? or is it ok to install as if I am upgrading
You're not connecting the VFD ground (from the VFD control voltage power supply to the BOB) to the system ground, are you? The VFD control voltage ground needs to be separate from the system ground, just like for the PC.
Regards,
Ray L.
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Well thanks for all the advice and help , with the patience and help of Chaoticone on the phone we went thru all the settings and got it all tuned up . As mentioned in his post above the pulley settings seemed to be the problem . Not sure which of these settings solved the problem but here are screen shots of the three screens where changes were made that solved my problem . Maybe these will help somebody else down the road
s1750 now gives 10.04v at the analog out , s875 = 5.09v and the actual rpm of the motor is within 10-15 rpm of the speed called out
Thanks Guys
(http://www.thompsonmachine.net/img/mhp/I1.jpg)
(http://www.thompsonmachine.net/img/mhp/I2.jpg)
(http://www.thompsonmachine.net/img/mhp/I3.jpg)
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:)
The two biggest settings were your max speed in config, spindle pulley and the velocity in config., motor tuning, spindle.
Glad your sorted.
Brett
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So what was causing the E-stop???
Regards,
Ray L.
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So what was causing the E-stop???
A conflict in the settings mentioned below and commanded spindle speed was causing the watchdor trigger. That is what was causing the e-stop.
Brett
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Thanks for info about REF ALL HOME. I still can't seem to get back to making parts. I had the machine running today to tweak it in and after about 20 cycles the Y axis just quit. The DRO continued to run for Y but no movement. Can't even get it to go with the jog function. I have shut the drive down still nothing. Is there some kind of error log that might indicate what happened? I will restart Mach 3 and see what happens. I don't have the Sola on the drive supply yet.
B.E.N.
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B.E.N.
Please reply in this thread , your posts have been split out to a thread of its own as it was off topic for this thread and also you are likely to get more views.
http://www.machsupport.com/forum/index.php/topic,8226.0.html
Hood