Can someone explain this given code?

Someone who will explain this given code.

Network 2:

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Thanks in Advance 

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Split from S5 to S7 upgradation problem in STL instructions.

 Hello hassaan,

Here's an explanation.

hassaanfaiz

Hello Experts, 

Someone who will explain this given code.

Network 1:

AN    M     20.1 (if M20.1 is not true then)

JC    M001 (jump to label M001 else)

OPN   DB   102  (open DB102 then)

JU    M002  (jump to label M002)

M001: AN    M     20.2  (if M20.2 is not true then) 

JC    M003  (jump to label M003 else) 

OPN   DB   103  (open DB103 then)

JU    M002  (jump to label M002) 

M003: AN    M     20.3  (if M20.3 is not true then) 

JC    M004  (jump to label M004 else) 

OPN   DB   104  (open DB104 then) 

JU    M002  (jump to label M002) 

M004: OPN   DB   101  (open DB101) 

M002: NOP   0  (no operation)

Network 2:

NOP   0

CALL  FC    11  (call and execute FC11)

NOP   0

//      CALL PB 15; (comments are not executed)

// *** Error in Line    2227  (FB   1):  Block does not exist. ***

NOP   0

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Thanks in Advance 

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Split from S5 to S7 upgradation problem in STL instructions.

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