Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: garhar1 on July 11, 2009, 12:20:04 PM
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Just starting. Xylotex board. Double checked wiring. Vrefs all 1.86V. VBB 24.8 V checked.
Set X, Y, and Z for pin 2, 3, 4, 5, 6, 7 Step Dir. Can't get limit switch ( when switched) to show on Diagnostics. Motors won' jog, although the position DRO moves when arrows pressed.
Tried Paralell Port BIOS settings of output only, bidirectional, EPP, and ECP, with no motro action on any.
Can some one point me in a direction?
Thanks,
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Correct port address set up?
Hood
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yes, 0x378. Check same on parellel port in hardware.
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Disconnect the parallel port cable from the computer and put a voltmeter between a Dir pin and a Gnd pin on the computers port then jog that axis, see if the voltage changes between 0v and 5v as you jog one way then the other. If it does then connect the cable up and disconnect the other end and check there.
Hood
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Hi, Garhar1
I responded to the same Question in FAQ section, http://www.machsupport.com/forum/index.php/topic,12032.0.html.
Please don't post the same question all over the place.
Thanks, Chip
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Put the question in the wrong spot.
The jumpers are there. I checked Sherline 1/2 step mode. Nothing.
I only have X stepper connected. I hit Y and Z jog. X moved in same direction with both Z up and Z down (pg up and down).
Tried it again with Sherline 1/2 step mode off, nothing. Turned on Sherline 1/2 step mode again, now nothing.
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Hi, Garhar1
It may be a LowActive setting issue for the one dir only problem, You'd think the MFG's would do a better job with a "link" to Good setup files.
Just use the pin numbers that move the X axis and change them from Z to X axis in Ports & pins.
Hears the Manual I think for your board, Sending a PM message to you.
Chip
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I'm reading 3.42 TO 0 volts on the parallel port out of computer.
PIN 2 PIN 3 PIN 4 PIN 5 PIN 6 PIN 7
X- ARROW LEFT 0.03V 3.42V
X+ ARROW RIGHT 0.03V 0V
Y- ARROW DOWN 0.07V 3.42V
Y+ ARROW UP 0.07V 0V
Z- PAGE DOWN 0.07V 3.42V
Z+ PAGE UP 0.07V 0V
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Ok so if I am understanding correctly pin 2 pin4 and pin6 toggle between 0v and 3.42 v when you jog each axis one way then the next? If thats correct then that is what you should see presuming you have 2, 4 and 6 set for Dir pins for their respective axis. 3.42 is a bit on the low side and it will depend on the drives whether it is good enough, dont know abiout xylotex.
Ok try at the other end of the cable now and make sure its going through the cable. If it is then looks like your problem is the low voltage.
Hood
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Chip,
The parallel cable fixed the problem. So the serial printer null modem cable was the problem.
Now that the motors are moving, I have a new issue: I can not get the program to reset without bypassing the estop and limit switches. I have 0 volts on the limit switch circuit. It goes to 5 volts when I open the sircuit (hit the limit switch). Active low is not checked. I see the pin LED light (in diognostics) when I open the circuit, but it will not reset.
Any ideas?
Thanks for the help.
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Hi, Rich
Not sure how you have your limits wired, Change the Active Low for all of the Home & Limit's should allow you to Reset. Just 1 Input Pin can do it if all SW's are wired NC and then in series to each other. One end to Gnd. the other end to an Input Pin.
Chip
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Chip,
This is exactly how I have the limits set (plus the estop). All are wired in series. All NC. If I hit one of the limit switches (with my finger), all the LEDs light in the configuration window. If I let go, they go out. But it won't reset. It says "external estop requested" and scrolls "press reset...emergency mode active".
Here is the port 1 pin state in the configuration window (x=on, o=off):
ooo*********oxoooo
oooooooooooo
If I hit the limit switch (capital X comes on):
ooo*********Xxoooo
oooooooooooo
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Settings page and Enable Auto Limits Override.
Hood
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Chip,
That didn't show well.
Try these screan shots:
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Auto limit override is enabled.
The before shot"
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Just reading again, how do you have the E-Stop wired?
Hood
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Can you attach your xml please and I will see what happens here with it, often easier to catch something that way.
Hood
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attached file
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Using limit switches as estop.
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All seems to be working fine here but I am just simulating the switches. Is there a chance that you have noise or a switch thats not closing correctly?
Hood
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No, switches are working properly.
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I have just tested with your xml and a switch connected between pin10 and Gnd and its working fine so not likely a config issue, almost definitely has to be hardware. I know you say the switches are good but can you test by removing the switches and just using a piece of wire connecting pin 10 to gnd and see what happens when you break then reconnect.
Hood
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I did that. When closed, I read 0.02 volts. When open I read 4.99 volts.
Also, when closed, there are no limit or estop LEDs lit in the configuration window. When opened, they light.
Is it normal for the 3 LEDs to be lit at all times (see before picture)? Could that be it?
garhar1
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Is it normal for the 3 LEDs to be lit at all times (see before picture)? Could that be it?
garhar1
Which LEDs are you meaning?
Hood
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Looks like the 0.02V is enough to keep it from resetting. If I bypass all the limit switches (and all the limit switch wiring running in the cable carrier) everything works fine. I guess I'm getting some bleed from the stepper wiring.
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Have you got the wires shielded and the shielding only grounded at one end?
Hood
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The stepper motor wires are shielded and ground at one end. I have nowhere to ground the other end. The limit wires are not shielded.
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Should only be grounded at one end anyway and ideally all shielding should be grounded to the same point in your control cabinet.
Hood
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I think its the cheap wire I used for the limit switch wiring. Time to rewire them. yuk
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Rewired and still the same problem. Searched the forum more and found I should set debounce to 500 to 2000. The 500 setting seems to have fixed the problem. Should have searched better the first time. Would have saved me a lot of time.
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Debounce only masks the problem it does not cure it as such, you will still have the noise or bouncing switch issue underneath. Personally I always say to people to set the debounce to 2000 and if it helps then the problem has been found and really it should be cured by properly shielding and grounding or getting switches that dont bounce.
Hood