First I need to tell what I use the system for.
I give old machines a second live by replacing an old and usually defective control system
Mostly bending machines. Due to the long tubes that are swinging around and the forces involved the emergency stop is extremely important.
For hydraulic machines this is simply a matter of cutting the valve tension and switching off the hydraulic pump.
The status of the machine cylcle stays unalterred and can be resumed or aborted as needed.
For servo it is completely different. It needs to be brought to a controled stop. (I think)
So I made a test program with 2 sequences
- abs, abs, abs, rel,rel, rel
- abs, rel, abs, rel, abs, rel, wich run perfectly, in both directions at will.
When I simulated an emergency I did the following:
I saved the complete input status of the servo axis
then I executed an axis stop and after the stop-done an axis reset
After reinstating the abs position or the rel distance, I put on target position or the remaining rel distance and the start bit again.
It would not resume where it left off. So maybe I should live with junking a halve finished product.