Changing the state of condition bit IR000.00 to ON starts the countdown (in this case for 27*0.01s=0.27 seconds). After the passing of given period of time, the appropriate bit IM003 changes state to ON, thus fulfilling the condition for executing the instructions on the right (in this case bit IR010.01 changes state to ON).

Condition bit must be constantly ON for a given time period for bit TIM002 to be set. If condition state changes to OFF during the given time period, timer resets and goes back to the beginning.

When the state of bit IR000.00 changes from OFF to ON, counter value decreases to 299, next change of bit IR000.00 lowers it to 298 and so on. When counter value reaches zero, state of bit CNT004 changes to ON, fulfilling the condition for executing instructions on the right (in this case, it is a normally closed contact that will open).

When the state of bit IR000.00 changes from OFF to ON, counter value decreases to 122, next change of bit IR000.00 lowers it to 121 and so on. When the state of bit IR000.01 changes counter value increases by one. When counter value reaches zero, state of bit CNT006 changes to ON fulfilling the condition for executing instructions on the right (in this case, it is normally closed contact that will open). ON state of bit IR00.02 will return the counter to a given value, while a bit CNT006 returns it to OFF state.

When the state of bit IR000.00 changes to ON, condition for comparing the values of memory locations IR200 and IR201 is fulfilled. If value of IR200 is greater than IR201, state of bit IR010.00 changes to ON. If value of IR200 is lesser than IR201, state of bit IR010.02 changes to ON. In case of equal values of locations IR200 and IR201, state of bit IR010.01 changes to ON.

When the state of bit IR000.00 changes to ON, condition for comparing the values of memory locations IR200+IR2001 and HR00+HR01 is fulfilled. If value of the first operand is greater, state of bit IR010.00 changes to ON. If value of the first operand is lesser, state of bit IR010.02 changes to ON. In case of equal values, state of bit IR010.01 changes to ON.

Comparation will be executed for as long as the state of condition is ON. If value of location HR00 equals “0210”, then it will be set between DM0014 and DM0015 correspoding to the second bit of the result word LR05.

Comparation will be executed as long as the state of bit IR000.00 is ON. If value of location HR00 is “0210”, then it equals the values of locations DM0002, DM0006, DM0010 and DM0014. Accordingly, the appropriate bits of the word IR216 change states to ON (they are set).

Upon fulfilling the condition on bit IR00.00, instruction moves the contents of memory location IR001 to memory location HR05. Every bit of word IR001 is copied to the appropriate bit of word HR05. Instruction MOV can be very helpful when reading the signals controller sends or receives from peripheral devices. Input states are moved to a working area, where they are processed and then they are sent to the output points of PLC controller.

Upon fulfilling the condition on bit IR00.00, instruction moves the complemented contents of memory location IR001 to memory location HR05. Every bit of word IR001 is complemented and copied to the appropriate bit of word HR05.

Upon fulfilling the condition on bit IR00.00, instruction moves the contents of ten memory locations IR200 - IR210 to memory locations HR00 - HR10.

Upon fulfilling the condition on bit IR00.00, instruction moves the contents of memory location IR000 (zero) to locations HR00 - HR05. In this way, it is possible to clear the memory block or to set it to a certain value. Same effect could be achieved if constant “#0000” was used instead of memory location IR200 containing all zeros.

Upon fulfilling the condition on bit IR00.00 instruction exchanges the contents of memory locations IR000 (all zeros) and IR201 (all ones). As a result, memory location IR201 contains all ones and memory location IR200 contains all zeros.

Bits 12-15 in the word LR10 from parameter C formthe number “0011”, which is in 0 - 8 range. Therefore, the instruction is used in the first form. Upon fulfilling the condition on bit IR00.00, instruction copies the constant #00FF to an address calculated by adding the base address (in this case HR10) and three lower numbers from the word LR10.

Bits 12-15 in the word IR216 from parameter C form the number “0101”, which exceeds 8. Therefore, the instruction is used in the second form. The example above shows how to create a stack between memory locations DM0001 and DM0005. Location DM0000 is used as a pointer marking the top of the stack.

Bits 12 - 15 in the word IR200 form “0”, while the rest of the word forms value 005, defining stack size to be 5 locations. Upon fulfilling the condition on bit IR000.00, instruction copies the contents of word LR00 to an address calculated by adding the address DM0000 with the shift defined in the word IR200 (lower three digits) : DM0000 + 005 = DM0005.

Bits 12 - 15 in word IR216 form a number “9”, while the rest of the word forms value 005, defining the stack size to be 5 locations. Number “9” as the first digit of word IR216 determines that the instruction works with FIFO stack. Upon fulfilling the condition on bit IR000.00, instruction moves the contents of the stack by one address, so that the element that first came into the stack (“AAAA”) is copied to the word IR001, while the stack pointer decreases by one.

Bits 12 - 15 of the word IR216 form a number “8”, while the rest of the word forms value 005, defining the stack size to be 5 locations. Number “8” as the first digit of the word IR216 means that the instructions works with LIFO stack. Upon fulfilling the condition on bit IR000.00, instruction copies the value of the last word that came into stack to the location IR001, while the stack pointer decreases by one.

Upon fulfilling the condition on bit IR000.00, instruction uses one-second clock on bit 255.02 in order to move the contents of the word HR00. Bit IR200.00 will be ON every time the bit HR00.07 equals one.

First instruction line determines the shifting direction, second determines input, third determines the clock and fourth determines reset. The shifting direction depends on the bit 12 of the control word. Depending on it, data bit moves to CY carry bit, while the opposite end becomes “0” or “1” depending on bit 13 of the control word. Condition for executing this instruction is located in the bit IR000.04, but besides this it is necessary to have the clock (bit 14 of the control word) ON. If the instruction is being executed with reset bit (bit 15 of the control word) OFF, all data bits as well as carry bit CY are set to “0”.

Carry bit status should be checked before the subtraction. It is best to clear it with CLC instruction. The check is more necessary after the subtraction, because there is chance of misinterpretation. If the carry bit is set (value is “1”) the result of subtraction is negative and the result word contains 10’ complement of the real result.
When the condition is fulfilled on bit IR000.02, carry bit is cleared and the value of memory location DM0100 is subtracted from value of location IR201. The result is stored in the location HR10. Upon subtraction, carry bit CY is checked. If it is set, condition on SR255.04 (the very carry bit) will be fulfilled, clearing it anew and commencing the new subtraction in order to get the real result of the first subtraction. The second subtraction instruction subtracts the value of the result word HR10 from zero, storing the result into HR10 again.
It is useful to set a certain bit for a programmer to have information on negative result. In the following example this bit is HR1100. Changing the state of carry bit to OFF doesn’t change the state of bit HR1100.

Character “@” ahead of SUB(31) represents the differencial form of the instruction, or simply put, this instruction will not execute non-stop while the condition is fulfilled. Only changing the condition from OFF to ON executes the instruction. This means that the second subtraction instruction won’t take place immediately after the first one. Before executing the second instruction, it is necessary that bit IR000.02 changed state from OFF to ON at least once.

Upon fulfilling the condition on bit IR000.00, instruction multiplies the values of memory locations IR013 and DM0005. The result is stored into two sequential memory locations HR07 and HR08. The result is stored so that HR08 contains higher bits and that HR07 contains lower bits.