Step7 - Can someone tell me what's wrong with this!

[L D[AR2P#0.0]]

Roy - when the plc stops you should be able to select the buffer entry for the alignment error and the OPEN BLOCK button should be available. Click on it and the block will open and the cursor will be at the line after the line of code where the error ocurred.
Again with the plc stopped, the Istack button should be available from the stacks tab, this will show you the registers etc.
The important thing is not to restart the plc until you have performed the above.

 

[RMA]

I ran the train into the buffers again and this time I remembered to copy all the stack info, including the call in OB1. As you can see, the address in AR1 is indeed a Bit address - but how come?

Oops, forgot to rename the files again - they'll soon be there!

 

[L D[AR2P#0.0]]

Did you do the open block to see which line it is stopping on ?

 

[L D[AR2P#0.0]]

I think I've got it. It is possible to jump to the "run" label without pntr (or the previous analogue) being calculated - hence the random value!

	 UN	#Start_Stop; //Are we in the active Step?
	  SPB   Exit; 
	  U	 #New; //Check for start of new run
	  SPB   run;

 

[RMA]

Did you do the open block to see which line it is stopping on ?

Yes and it is stopping on the transfer in NW2, however, your point about the jump to "run" sounds like it might be the explanation. I'll go and check that out.

 

[RMA]

Thanks Simon,

that was indeed the problem. I've moved the Temps onto Marker Words and now everything's working fine.

Cheers

Roy