[NJC]

I accidentally reset one of the limits on the control and now have this alarm that I can't get rid of, can someone walk me through how to reset the limits?

Thanks!

[broby]

What control system are you using? What machine? Which axis?
OSP5000, 7000, U100 blah blah blah...
Basically the procedure is the same, just the screen might be slightly different.
You need to also find the configuration card in the back of the machine, that should state the original value when the machine was delivered.
Depending on the history of the machine, the stated values may be close to what you need or way way off... All comes back to in the System Zeroset value has been altered significantly or not.
Go to the Parameter page and find the screen that is used to display/set system parameters, not the "User" parameters.
What you need to do is set the System parameter for both the Positive and Negative ends of axis travel.
On the "User" parameter screen, the Positive and Negative values must lie between the values set on the System Parameter page, otherwise you will not be able to move.
Also, if the parameter values are swapped, you will not be able to move either!
OK, so with the values from Install handy, compare them to the values currently set on the "System" parameter screen for the desired axis, WRITE the existing values down BEFORE you start changing them! (covers the 'Oh Crap' factor!).
"Set" the values from the install card and see if that helps.
If the encoders have been changed or moved at any stage, resulting in a change in the System Zero value the values will probably not help much, all you can do then is keep altering the parameters a little bit at a time.
Keep in mind also, are you sitting on the limit switch? If so you will need to turn on the Overtravel Release switch and attempt to move the axis off the limit by using the handwheel in manual mode.
When doing it by trial and error, keep an eagle eye on the physical position of the slide! you do NOT want to hit the physical limit on the machine and do any damage... not good.
Keep the changes small and gradual and you should work it out.

Basicall you need this condition...


* 1 2 -------------------- 3 4 *

Where the first * is the absolute physical negative limit (do not hit this one!)
1 represents the System maximum negative limit position (safe to run into this one)
2 represents the User Negative limit (ok to run into)
the ------- represent the normal operating area of the stroke.
3 represents the User Positive limit (ok to run into)
4 represents the System Positive limit (ok to run into)
the last * represents the physical positive limit (do not hit this!)

Hope this long winded dialogue helps in some little way.
Regards
Brian.

[NJC]

Hey Brian, thanks for the reply!

So I entered the values from the build card in the "system params", turned the OT switch and it moves all but in x pos, will only move neg, can you take a look at my values and suggest what change to make? Should the changes be made to the user or system values?

Here's what I have in "user" params

+ Variable limit (prog) X -110.9922 Z 15.5929
- Variable limit (prog) X -122.0159 Z -4.8796

+ Variable limit (mach) X 485.8272 Z 259.8583
- Variable limit (mach) X 474.8035 Z 239.3858

Thanks for the help,
Scott

[broby]

Hey Brian, thanks for the reply!

So I entered the values from the build card in the "system params", turned the OT switch and it moves all but in x pos, will only move neg, can you take a look at my values and suggest what change to make? Should the changes be made to the user or system values?

Here's what I have in "user" params

+ Variable limit (prog) X -110.9922 Z 15.5929
- Variable limit (prog) X -122.0159 Z -4.8796

+ Variable limit (mach) X 485.8272 Z 259.8583
- Variable limit (mach) X 474.8035 Z 239.3858

Thanks for the help,
Scott

Hi Scott,
Rather difficult to say from the values supplied as the (prog) values will change as the zeroset changes.
The fact that you can move the machine, even if it is only in the negative direction, is good. That means that at least some of the values are within the "allowable" range.
Is the machine clearly not on a limit now?
One way you can set "user" limits is to highlight the limit value, pos or neg, and then press "CAL" & then "Write".
This will set the "user" limit position to where the machine is currently at.
From there try adding to the "user" limit position say 1mm at a time and try moving the machine.
BTW, with the Overtravel release switch ON, you can only move "away" from the overtravel switch, even if you are clear of the switch.
One sure way of setting the "System" limit position is to very slowly move the machine towards the stroke end looking for the machine to alarm out. "Calculate" this position and record it. Now add some arbitrary amount to the "User" limit at this point to prevent the machine from hitting the switch. Once your "User" value is set and you can rapid up to the limit without the alarm tripping, "Set" the value in the "System" value for that axis.
Do that for each end of each axis and you should be on your way.
so. in simple man terms...
Set your "System" limits way apart, with "Overtravel" release OFF, use the pulse hand wheel to move the machine onto the limit switch.
Record the position using the "User" limit.
Move off this position by maybe 1mm and then use that position as the "System" limit position.
Repeat at each Axis Stroke end.

Cheers
Brian.

[broby]

Hey Scott,
Forgot, once you establish the new "System" limit values, WRITE THEM DOWN on the install card and date the entry!
Any time the machine undergoes maintenance that involves removal of the encoders, you will need to reset the "System" limits anyway!
Cheers
Brian.