Crack plc's time bomb - Database & Sql Blog Articles

SMD aluminum electrolytic capacitor

Probe orientation needle 265*2980, needle head diameter is 6.0, end probe needle

Open the PLC ladder diagram.

During each scan cycle, 335 lines are added, and the result is stored in D2888. Line 343 represents the last two digits of the year, which equals the decimal value 5—meaning 2005. The month is represented by the decimal value 6, so it corresponds to June. Therefore, this line indicates June 2006.
Both line 354 and line 362 contain conditional jumps to P6. If you look closer, this jump only covers up to line 371. What line 371 does is clear all outputs and then jump to P9. This suggests that if either line 354 or 362’s condition is met, the program will move to P6.
Before the "bomb" M888 was triggered, the system operated normally via the jump instruction on line 362. Once M888 is activated, it remains active because it's a power-off retention bit. So, if you don’t want to jump to P6 on line 354, the program will have no output at all.
A direct solution is to bypass this "bomb" by inserting a line just before line 254 that jumps directly to P6. Alternatively, you can set D2888 equal to the decimal number 7817. Since D2888 is the sum of D2845 and D2850, converting this value to hexadecimal reveals that as long as their total is hex 313, the bomb can be neutralized. This gives us the key to disable the trigger safely.