Could you Explain Fanuc Robot RJ 3 Code Segment

I lost my programming manual for a Fanuc Robot. Could you
explain this small segment of code. The segment is controlling
a measurement of a pallet height ,so it can start stacking.
I'm sorry I should know this.
Thanks, it as been 2 years since I somewhat understood the code.

26: !searching ;
27: SKIP CONDITION RI[4:lower off]=ON ; What is the Skip Condition
28:L PR[92:S2] 600mm/sec FINE ACC150 Skip,LBL[30]; What is S2
29: ;
30: !read actual position ;
31: PR[93:S3]=LPOS ; What is S3 and LPOS
32: ;
33: OVERRIDE=R[22verride act] ;
34: R[19:measure]=PR[93,3:S3]+R[20:measure corr.] ;

The Skip Condition is a condition handler. I'm not sure, but I think the way it works is when the I/O condition that is defined in this statement becomes true, the motion statement that contains the Skip LBL is interrupted and the next line is executed. If the motion is completed and the condition is still not satisfied, then the program will jump to wherever that label is and continue from there.


As far as S2 and S3, I think those are just the names that the original programmer has given to those particular Position Registers.
PR[93:S3]=LPOS Places the current cartesian coordinates into Position Register 93.

we use this to do searches on stack a metal
the skip is set up on line 27 and the robot will move to L PR[92:S2] if RI[4:lower off]=on while it is moving to L PR[92:S2]it stops the move and goes to the next line. if the robot makes it to point L PR[92:S2] before RI[92:S2] turns on it Skips to LBL[30]