When is "s" supposed to stop motion

While running a simple program

 

while(1 == 1) {

X10 F100

x-10

}

 

Issuing an S command with Coord[x].NoBlend=1 finishes the execution of the current line and then runs the next line.

 

Issuing an S command with Coord[x].NoBlend=0 finishes the execution of the current line and then runs 2 subsequent lines.

 

I would expect a motion controller to pause the program at the end of the current line providing your not already passed the point where deceleration can occur.

 

Have I got something wrong?

Step stops execution at the end of the calculated move. What you describe is how it should work. You must always consider the difference between calculated moves and executing moves. In the PowerPmac training slides (slide packet 18 in the file depot) you can read about these details.

That's not the answer I'm looking for.

 

I'm currently investigating the possibility of moving our CNC machine to the Power PMAC. We currently use the Turbo UMAC and have used the PMAC, PMAC2 and Galil. Our company also use Heidenhain, Siemens and Fanuc controllers. In every case the user could select single block and reasonably expect the machine to finish the current move and stop.

 

There is absolutely no way that I could sell this behaviour to my company or my customers.

 

I'm hoping that among the plethora of options their is something that can make the system act in a more sane manner.

This brings up a question. You say you have used Turbo Pmac. The Power Pmac works the same as Turbo Pmac. How did you solve this on Turbo Pmac?

The already calculated move is what you are seeing. In this case if blending is on, Coord[x].NoBlend=0, then PMAC will include the already calculated move on the first occurrence of the step command. Subsequent step commands will not “look-ahead” and only execute the next move block. On issuing your first step command instead issue a quit command. PMAC will not include the “extra” move. Note that this is documented in the description of “s” command in the Power PMAC Software Reference Manual.

This brings up a question. You say you have used Turbo Pmac. The Power Pmac works the same as Turbo Pmac. How did you solve this on Turbo Pmac?

 

That's interesting, the code on the Turbo did not use the Q command it only used the S command and it performed as I would have expected. As I write this I'm feeling obliged to go and check the Turbo code.....

 

The Turbo code never issued a Q command