5-150 M60 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUALFLEXLOGIC CHAPTER 5: SETTINGS5Figure 5-69: FlexLogic equation for virtual output 47. Now write the complete FlexLogic expression required to implement the logic, making an effort to assemble theequation in an order where Virtual Outputs that are used as inputs to operators are created before needed. In caseswhere a lot of processing is required to perform logic, this can be difficult to achieve, but in most cases does not causeproblems as all logic is calculated at least four times per power frequency cycle. The possibility of a problem caused bysequential processing emphasizes the necessity to test the performance of FlexLogic before it is placed in service.In the following equation, virtual output 3 is used as an input to both latch 1 and timer 1 as arranged in the followingorder:DIG ELEM 2 OPCont Ip H1c OnNOTAND(2)= Virt Op 3Virt Op 4 OnVirt Op 1 OnVirt Op 2 OnVirt Ip 1 OnDIG ELEM 1 PKPXOR(2)Virt Op 3 OnOR(4)LATCH (S,R)Virt Op 3 OnTIMER 1Cont Ip H1c OnOR(3)TIMER 2= Virt Op 4ENDIn this expression, the virtual output 4 input to the four-input OR is listed before it is created. This is typical of a form offeedback, in this case, used to create a seal-in effect with the latch, and is correct.8. Always test the logic after it is loaded into the relay, in the same way as has been used in the past. Testing can beFlexLogic entry:Virt Op 3 On (VO3)FlexLogic entry:OR (4 Input)FlexLogic entry:Latch (Set, Reset)919293FlexLogic entry:Dig Element 1 (DE1) PKPFlexLogic entry:XOR (2 Input)8990XORFlexLogic entry:Virt Op 1 On (VO1)FlexLogic entry:Virt Op 2 On (VO2)FlexLogic entry:Virt Ip 1 On (VI1)868788FlexLogic entry:Virt Op 4 On (VO4)85FlexLogic entry:=Virt Op 4 (VO4)99FlexLogic entry:OR (3 Input)FlexLogic entry:Timer 2969798FlexLogic entry:Virt Op 3 On (VO3)FlexLogic entry:Timer 19495LatchResetSetORORT1T2 Virtual output 4827031A2.CDRFlexLogic entry:Cont Ip 2 On (H1c)
