Discuss Thermwood 3-axis Machinery, Controller, and Software.

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Michael J Starry
Junior Member
Posts: 29
Joined: Tue, Oct 03 2006, 9:40AM
Location: Brainerd, MN


Postby Michael J Starry » Tue, Nov 27 2007, 8:14AM

So, what is the deal with the M241(ghost macro)? I know it magically appears if you E-Stop during any part of a tool change. But why? Where does it come from, why is it there and why does there seem to be no real fix for it?
I know you reset and home, reload the program, run rebuild and all that, but why the workaround? What is the root cause? It just seems odd to me that this macro can simply manifest itself at will just from hitting the E-Stop button, then create all kinds of issues if you don't realize it is there. Which, incidentally, is typically the case when you have as many operators as we do. They are not all well versed in the subtle nuances of the Thermwood controls, they are just operators with only rudimentary skills. When something like this happens, it always leads to a loss of an hour or production time while they try over and over again to run a part, then get a super and/or maintenance, until someone finally comes and gets me to solve the problem.
Okay, rant over...... But really what is the deal with it? Any ideas?

Carl Jones
Thermwood Team
Posts: 46
Joined: Fri, Mar 16 2007, 7:46AM

M241 macro

Postby Carl Jones » Tue, Nov 27 2007, 10:51AM

Hello Michael, the 241 macro can be entered into a program by the plc if the machine is e-stopped during a tool change. It doesn't necessarily happen every time the estop is pressed during a tool change routine.The older SIO systems process information a little slower than the new digital Gen 2 controls, which increases the chances of this happening. This is why it happens....During a tool change routine, the plc is entering macros in the program and running them. After the toolchange routine is finished the plc deletes those macros. If the machine is e-stopped during this routine at a particular place in the routine, the plc doesn't have the chance to delete those lines. Therefore, you get the \"ghost macros\" entered into the program. There isn't a \"fix\" for this. What you can do if this happens is, reload or re-nest the program without saving it and it will be the original you were running previous to the error. Or, you can simply go to the point in the program and delete the M241 and the M0 that it added. Also, check the screen to see which tool the machine thinks it has, and physically switch it if incorrect.
Thermwood Technician

Nemanja Vujkovic
Senior Member
Posts: 222
Joined: Wed, Feb 21 2007, 1:29PM
Location: STL, MO

Postby Nemanja Vujkovic » Tue, Nov 27 2007, 10:55AM

If you go to C drive, macros foldr, find the macro that you want to check.
M241 is for tool changing! It does not magically appear, its allway there when tool change is in progress!!!

Ryan Hochgesang

Postby Ryan Hochgesang » Tue, Nov 27 2007, 11:46AM

To add to this topic, I've seen in other cases were operators are using the estop as stop when hesitant about running a program for first time, this interupting near the tool change etc... I typically recommend to place the M48 code in top of program to check the program for first time and have FULL control over program with Feed Control Knob, rather than constantly E-stopping machine at every bit of hesitation, just turn feed control knob to zero. Once the program has been tested, remove the M48 and NC Reset machine to continue production with a lesser cycle time.

The other potential cause of the situation your seeing could be due to underlying conditions causing your ESTOPs. Is the actual ESTOP being pressed or is this particular machine encountering a fault of some kind?
If there is a fault occuring, it would be best to resolve cause of the fault to reduce the occurrances of the \"ghost\" macro being written. When estop occurs, the PLC screen can be veiwed for information (F10, F3, F5) regarding the condition. For example: I've seen in facility's where the air pressure supplied to the machine would drop randomly causing the estop condition, this coincidentally happening at a toolchange.

Michael J Starry
Junior Member
Posts: 29
Joined: Tue, Oct 03 2006, 9:40AM
Location: Brainerd, MN

Postby Michael J Starry » Tue, Nov 27 2007, 1:37PM

Interesting that it happens. That it will add it to the program like that. Our situation is always that an operator hits the E-Stop. I always have M48 in my program, but that doesn't help much if the operator still thinks the tool will hit the part or what have you. They will still squash the stop.
It does still seem strange to me that the THM software/controls are able to add a line of code into my program. I know the macro is there, in the background, but the fact that it will insert itself into my existing program is a little weird to me, but oh well.
Thanks for the input guys.

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