Issue in STL (Siemens S7 300)

I'm not used to program in STL and I have some issues in set (S) and reset (R) instructions in the following commands:

====================
Network 48
A(
O "DB_010TT1".SOLVE.ALLOW_TABLE_1_TO_LOAD
O "DB_010TT1".SOLVE.ALLOW_TABLE_2_TO_LOAD
)
A(
L "DB_010R01".AUX.CODE_PRG_ARM2
L 0
<>I
)
S "DB_010R01".SOLVE.AUX_START_PROG_ARM2
A "DB_010R01".INPUT.ARM_2.PROGRAM_ACTIVE
AN "DB_010R01".SOLVE.NO_PRG_RUN_ARM_2
R "DB_010R01".SOLVE.AUX_START_PROG_ARM2
NOP 0
====================

As a begginer in STL, I did not understand if the RLO bit is set in each line and applied to the next line.

My issues in this program are:

1.If the first two AND instructions are true, "DB_010R01" is set to 1?
2.If one of the first two AND instructions are false, "DB_010R01" is set to 0?
3.If "DB_010R01" is 0, the following AND and AND(negated) are executed?
4.Afther the AND and AND(negated) execution, "DB_010R01" can be reseted to 0 according to the logic result?

If the first two ANDs are true, "DB_010R01".SOLVE.AUX_START_PROG_ARM2 is set to one. Note the string in quotes is the DB symbolic name, while the actual bit is .SOLVE.AUX_START_PROG_ARM2.

The AND and AND NOT after the SET instruction are evaluated separately from the SET, regardless of the state of "DB_010R01".SOLVE.AUX_START_PROG_ARM2
Now I need to double-check the Hans Berger book to explain why...

My take on it as ladder

Steve

read L as set and U as reset

Thanks for the quick answer!

Did you try to switch your view to LAD ? the NOP 0 gets me thinking this was not human-made STL.

nehpets: your second rung show an OR, I think it should be an AND

wimpiesplc,

You are right, I stand corrected the two instructions in the second rung should be in series not parallel.

Regards
Steve