TILI Automation

 To study the working of Up Counter PLC program in Allen Bradley Programmable Logic Controller (PLC). Down Counter In the above picture, there are totally three parameter, COUNTER: C4:0 – Counter File name (TimerC5:0, C5:1,C5:2…) PRESET – PRE : Limit value of COUNT-Up to how much it should count ACCUMULATOR – ACC : Running Value of counter when condition turn ON. From the data file,along with preset and accumulator, we have few more bits, CD: Countdown Bit-whenever the counter is enable makes this bit to go ON. DN: Done Bit-When accumulator value equals preset value, done bit turns to ON. UA: Counter Underflow – When accumulator value reached the limit value (-32767),it rolls back to +32767 for the upcoming counter operation, underflow bit turns ON, in this condition.   Notes: UA – Update Accumulator Value-Only used when high speed counters are used in the program. CU & OV – Used for Up Counter Function. Down Counter Description Using PLC Program I:0/0 is used to give inpu...

 Build the ladder logic example with Timers to turn ON/OFF the lamp using push buttons with respect to program logic conditions. PLC Logic 1. Start PB and Stop PB are to turn ON and OFF the lamp. 2. After Start PB is pressed, In the following sequence Outputs should turn ON/OFF Q1 is turn ON for 5 sec Q2 is turn ON for 5 sec Q3 is turn ON for 5 sec Q4 is turn ON for 5 sec 3. End of above sequence will trigger, All four outputs (Q5, Q6, Q7, Q8) to turn ON. In the following sequence, outputs should turn OFF after its turned ON, After 5 sec, Q5 should go OFF After 5 sec, Q6 should go OFF After 5 sec, Q7 should go OFF After 5 sec, Q8 should go OFF Note: Process should continue until stop PB is pressed List of Inputs and Outputs Ladder Logic Example with Timers Logic Description RUNG 0000 Latching rung to operate the system through Master Start and Stop PB. RUNG 0001 Latched B3:0/0 is connected with T4:0 which starts running. Normally closed contact of T4:1 timer done bit is connected t...

 In the ladder logic diagram we can see there is an input contact (N-O) “I0.0” which is a toggle switch in the physical connections to the plc. There is also an output coil addressed as “Q0.0” which can be a Motor, Bulb or any signaling device in the physical connection. Ladder Logic Now, as soon as toggle switch is pressed the NO contact of I0.0 becomes NC and the corresponding rung logic goes true. As a result output coil Q0.0 gets energized and the bulb will ON. On the other hand, if we want to switch OFF the bulb, the toggle switch is again pressed and I0.0 again becomes an NO contact and rung goes false ,which in turn switches OFF the bulb. -END-

 Learn how to use Single Push button to ON and OFF a Bulb using Ladder Logic in programmable logic controllers (PLC) control system. I0.0  : Input Push-Button (Normally-Open) Q0.0 : Output Coil (Bulb) Q1.5 & Q1.6 : Flags Single Push button Ladder Logic As soon as the push button I0.0 (N-O) is pressed ,it becomes N-C and coil Q1.5 (flag) is energized. The another flag Q1.6 will not energize as the output coil contact  Q0.0 is N-O, which breaks the circuit to the flag Q1.6. As soon as the flag Q1.5 is energized ,the contact Q1.5 (N-O) becomes N-C and out bulb coil Q0.0 gets energized and bulb becomes ON. Now, if the push button is released the coil Q0.0 will remain energized because of latching applied as latch contact Q0.0 (N-O) in last rung. To switch off the bulb the push button is again pressed which closes the N-O contact of o/p coil Q0.0 and energizes the flag coil Q1.6. Due to energize of flag Q1.6 , the N-C contact of this flag in last rung becomes N-O  and...

 Design a ladder logic for Go-Down wiring for 3-rooms using plc programming and explain the Concept of Interlocking in PLC programs. I0.0 , I0.1 , I0.2 : Toggle switches of corresponding rooms 1, 2, 3. Q0.0 , Q0.1 , Q0.2 : Output coils (Bulbs) in room 1, 2 ,3. Interlocking in PLC Seeing the ladder diagram we can infer that as soon as the person enters into room 1 and switches ON the toggle switch 1 (I0.0), the bulb of that room  glows i.e, coil Q0.0  in rung 1 gets energized. Now, the person moves into room 2 without switching OFF the toggle switch of room 1. As soon as he/she presses the toggle switch 2 (I0.1), the bulb of that room (Q0.1) starts glowing as its coil gets energized, while the bulb of room 1 itself goes OFF as its circuit is break by the interlock contact Q0.1 in rung 1 which is (N-C) type. Similarly, when the goes into room 3 and presses switch 3 (I0.2) , the bulb of room 3 starts glowing and that of room 2 switches OFF keeping the bulb of room 1 already ...

 Design the ladder logic for controlling the running state of the single phase motor by pressing START and STOP pushbuttons i.e. motor should remain in ON state after START pushbutton is pressed and should OFF when STOP pushbutton is pressed. We also have to check if the motor is running normally by pressing TEST pushbutton? I0.0 – START pushbutton to Start Motor I0.1 – STOP pushbutton to Stop Motor I0.2 – Error signal from Motor to PLC. Q0.0 –Single phase Motor PLC Motor Logic Press START button and I0.0 is ON. The Motor will keep running if no error occurred (I0.3 is OFF). The action can be practiced by a latching circuit which takes output Q0.0 as one of the input condition to keep the motor running even if the START button is not pressed (See normally open contact Q0.0 below I0.0). When STOP button is pressed, I0.1 is ON and Q0.0 is OFF. The motor will stop running. If any error is occurred (I0.3 is ON), Y1 will be OFF and the motor will stop running. When TEST is pressed (I0.2...

 Design Ladder Logic for Stair-Case wiring using two Toggle Switches in programmable logic controllers (PLC). I0.0 & I0.1 : Input toggle switches. Q0.0 : Output signaling device(bulb, motor etc.) Ladder Logic for Stair-Case wiring This ladder logic of stair-case wiring works on the X-OR logic i.e, Y is (A.B^) + (A^. B) Suppose initially only I0.0 is pressed and I0.1 remains open physically as shown then the upper branch of rung 1 goes TRUE  and Q0.0 gets energized. Now , if I0.0 is also pressed then it will make its interlock N-C contact I0.1 to go open and as a result Q0.0 de-energizes . Again, if switch I0.0 is pressed it will also make its interlock contact I0.0 in parallel branch to go again N-C , which in turn makes the parallel branch logic true and Q0.0 again energizes but if the I0.1  input is also pressed again the logic goes FALSE and Q0.0 again de-energizes. This is the basic concept of an X-OR logic gate.