Tool Changer logic

[69owb]

Hi
I’m having problems with the logic for my tool changer. I can’t seam to figure out why the logic will not work right. I’ve looked at the program for so long that I don’t know if I’m not seeing the problem or what?
Here’s some of the back ground. It has 20 tools 1-20 in a counter clockwise rotation. Lets say you have tool #8 in the spindle and you call Tool #6 the tool carriage should rotate counter clockwise. When you run the program it will rotate clockwise. I basically copied this part of the program from the book anybody see anything wrong with this statement. In the log file the variable \95 shows -2 so that tells me that it is doing the math right but it seems like it reads the first If statement then it turns on #22?
DISPVARB \90
READVARB \90
'Subtract current tool from last tool
\95={t-\90}
DISPVARB \95
'Start the tool changer motor rotating CW
IF \95> -10 THENIF \95<=0 THEN #22=1
'Start the tool changer motor rotating CCW
IF \95<= -10 THEN #21=1
'Start the tool changer motor rotating CW
IF \95> 0 THENIF \95< 10 THEN #22=1
'Start the tool changer motor rotating CCW
IF \95>= 10 THEN #21=1

[Karl_T]

I can only suggest a change in approach to solving your logic issues. Break the problem into small little pieces - your chances of dropping a large chunk of logic in and having it work right away are slim. When it don't work, finding what it is can be bewildering.

First, doulble and triple check that every Input and Output works EXACTLY as you think it should. I can't emphasize this enough.

Then get a small piece of the logic working right. Start with just a few lines of your tool changer program. Then add a line or two and try again. Work your way through it.

The logfile can be very useful but becomes impossible to follow when you have a ton of I/O changing state. (That will be your case here) Every change of I/O causes the entire inputio file to run. To solve this I pepper the heck out of my trial logic with MESSAGE statements. Display every single value to the screen and exactly where you are in the program also.


Your issue for the moment is to find exactly what line you're on when the tool changer runs the wrong way. And recheck that that output does what you think it should. Did I mention BE SURE ALL your I/O does exactly what you think it should?

Oh, by the way, did I mention that not having a firm fix on exactly how the I/O is working can be your biggest problem?

Karl

[69owb]

Hi
I was thinking on looking at the i\o's to double check that they are turning the right way. Otherwise the rest of the program seams to work fine its just that part of the logic that’s giving me a headache. I'll copy part of the logfile and post it later.