How to use M2 and M30？

hi,
When I use the G code, I see that M2 and M30 both end the program, M2 ends directly, and M30 ends after changing the pallet shuttle. How should I test this? How to distinguish between them?I can't see the difference between them . m2-m30，
   
 

andypugh wrote:

I wonder what this ought to do?

Is it as simple as driving / responding to pins pallet-shuttle and pallet-shuttled?

Yes, I want to demonstrate the functions of M2 and M30, but I don’t know how to test M30. It has the same function as M2. How to test M30?Or how can I show the difference between M2 and M30?
thanks，chen

andypugh post=223888 userid=723我觉得M2和M30唯一的区别就是调用了PALLET_SHUTTLE，它什么都不做：

https : //github.com/LinuxCNC/linuxcnc/blob/master/src/emc/rs274ngc/interp_convert.cc#L4389

有意思在我从事 LinuxCNC 工作的所有时间里，没有人问过为什么托盘穿梭机不起作用。

Possibly, I don't know what the pallet shuttle does.