EXPERIMENT 1 AIM: To study the terminology and LADSIM software and develop simple basic circuits on software using input and output and develop AND, OR, and Not circuits. SOFTWARE REQUIREMENT: LADSIM software THEORY: LADSIM stands for LADDER SIMULATOR, is a fully-functional Ladder Logic Editor and PLC Simulator that incorporates all the basic functions used in PLC Programming. With Inputs, Outputs, Timers, Counters, Flags and Shift Registers available, we can develop ladder programs quickly and easily. Each function is simply 'dragged' onto the ladder rung with name tags assigned via a pop-up window. Extra rungs can be added with the click of a button, together with branches to form more complex programs. LADSIM incorporates seven 'real' process simulations that will test our understanding of Ladder Logic Programming. For each simulation we must develop the necessary ladder code to effect safe control of the scenario. The simulations provided within LADSIM are a Traffic Light, Annunciator, Car Park, Lift, Drinks Machine, Packing Line and Bottling Plant. While LADSIM can be used as a stand-alone teaching aid with its library of internal simulations, it also has the added benefit of being capable of controlling external applications via one of our PC Internal Interface cards. The LADSIM Editing Screen The main screen of LADSIM is where the main ladder program is created. 1. The Ladder Logic Diagram Window: This is where the ladder code is displayed. Each time you add or edit a rung, the result will be shown here. Fig1. Ladder logic diagram
2. The Controls box: This contains the ladder symbols that are used to create the ladder diagram. See below for further details. Fig2. Control box 3. The toolbar: This includes the standard buttons of LADSIM and allows you to start a new diagram, open an existing file, print, save and comment your ladder diagram. Fig3. Tool bar The LADSIM Controls 1. Ladder logic programs are made up of symbols that represent the various inputs and outputs of the plant equipment we wish to control. LADSIM uses the same symbols to produce the ladder code on screen and each one is defined below : 2. LADSIM features a total 12 inputs, 12 outputs, 8 timers, 16 counters, 16 flags, 4 shift registers and 12 reset functions for the timers and counters. Creating a Ladder Diagram
1. A ladder diagram can be quickly generated by 'dragging' the required controls from the control panel and dropping them on the rung. In LADSIM, once we have dropped a control onto a rung, a box appears where we can enter information about that control. Fig4. Dragging a rung Testing your Diagrams Once you have created a piece of ladder code it is important to ensure its correct operation before applying it to a real control problem. LADSIM has a unique testing facility built into the package so you can test and debug the ladder programs created in LADSIM. The Debugging Simulator is activated by clicking on the simulate button or the debugger from the simulate menu. LADSIM's debugging simulator gives you access to the various inputs used in your program. Here you are able to force the inputs simply by clicking on the button and examining the result. All the information provided will help with the debugging and testing of your ladder diagram within a safe environment. Fig5. Debuggig simulator
PROCEDURE: Following are the steps to be followed to create AND, OR and NOT circuits in LADSIM software: AND Gate: The AND gate is a basic digital logic gate that implements logicall conjunction - it behaves according to the truth table given below. A HIGH output (1) results only if both the inputs to the AND gate are HIGH (1). If neither or only one input to the AND gate is HIGH, a LOW output results. In another sense, the function of AND effectively finds the minimum between two binary digits, just as the OR function finds the maximum. Therefore, the output is always 0 except when all the inputs are 1s. INPUT OUTPUT A B A.B The AND gate with inputs A and B and output C implements 0 0 0 the logical expression. 0 1 0 1 0 0 STEPS: a) Open the LADSIM software. Go to the toolbar, click file tab and select new. 1 1 1 b) Now the ladder logic diagram window will be open. From control box select add rung. A new rung is added to the ladder logic diagram space. c) After adding rung go to the controls where we will see the symbols of inputs, outputs etc. select input with symbol as input and drag it to the rung named rung 0. d) When we place the input in the space a new window will open showing the input name. Select the new input as input0.
e) Again repeat the step (C), and (d). Name the new input as input1. The new input input1 is placed in series with the input0. f) Now from the controls table select and drag the output symbol to the rung0. A new window will be open showing various outputs, select the output0. g) Now go to the control table and press the button to open the debugging simulator window. h) Close the input0 and input1 together to get an output. The high output is indicated by the red signal.
OR Gate: The OR gate is a digital logic gate that implements logical disjunction - it behaves according to the truth table given below. A HIGH output (1) results if one or both the inputs to the gate are HIGH (1). If neither input is high, a LOW output (0) results. In another sense, the function of OR effectively finds the maximum between two binary digits, just as the complementary AND function finds the minimum. The OR gate with inputs A and B and output Q implements the logical expression Q = A+B. INPUT A B OUTPUT A + B 0 0 0 0 1 1 1 0 1 1 1 1 STEPS: a) Open the LADSIM software. Go to the toolbar, click file tab and select new. b) Now the ladder logic diagram window will be open. From control box select add rung. A new rung is added to the ladder logic diagram space. c) After adding rung go to the controls where we will see the symbols of inputs, outputs etc. select input with symbol as input and drag it to the rung named rung 0. d) When we place the input in the space a new window will open showing the input name. Select the new input as input0.
e) Again repeat the step (c), and (d). Name the new input as input1. The new input input1 is placed in parallel with the input0. f) To place new input parallel to the previous one, select from the control box, and specifies the location of the new branch as per the given fig below.
g) Now from the controls table select and drag the output symbol to the rung0. A new window will be open showing various outputs, select the output0. h) Now go to the control table and press the button to open the debugging simulator window. i) Close either the input0 or input1 to get an output. The high output is indicated by the red signal.
NOT Gate: In digital logic, an inverter or NOT gate is a logic gate which implements logical negation. The truth table is shown on the right. INPUT OUTPUT The NOT gate with inputs A and A NOT A output OUT implements the logical expression OUT = NOT A. 0 1 1 0 STEPS: a) Open the LADSIM software. Go to the toolbar, click file tab and select new. b) Now the ladder logic diagram window will be open. From control box select add rung. A new rung is added to the ladder logic diagram space. c) After adding rung go to the controls where we will see the symbols of inputs, outputs etc. select input with symbol as input and drag it to the rung named rung 0. d) When we place the input in the space a new window will open showing the input name. Select the new input as input0.
e) Now from the controls table select and drag the output symbol to the rung0. A new window will be open showing various outputs, select the output0. f) Now go to the control table and press the button to open the debugging simulator window. g) Close the input0 and the output is always low. The low output is indicated by the black signal. As soon as the input is open the output is high, and the high signal is shown by the red signal.
RESULT: The terminology and LADSIM software is studied and simple basic circuits AND, OR, NOT on software using input and output were developed.
EXPERIMENT-2 Aim-To study the use of latch, timers, counters,bsr,bsl in LADSIM Software. Equipment\Hardware Required-Networked Computer Software Requirement-LADSIM Software Theory-Latch is a retentive output instruction. Latch can only turn on a bit. This instruction is usually used with Unlatch with both Latch and Unlatch addressing the same bit. Actuating the latch input turns the function on or causes it to change state. The function then stays on even if the latch input is turned off. To turn the function off, another input must unlatch which turns the function off. With timers, counters one can edit their ladder code easily and quickly. A counter might be used to count up or count down and then activate a contact. When counting down, you must also enter a number in the accumulator equal to or smaller than the count. The contacts close when the accumulator is decremented to zero. When counting up, you should have zero in the accumulator and the contacts close when the accumulator is incremented to the same value as the number of preset counts. Each time a BSR( bit shift right) is done with bit 15 being replaced by a 0, the binary number is divided by two. If BSL is used (Bit Shift Left), all the bits are shifted left with the LSB being replaced by a zero, the binary value is doubled. Using LADSIM diagram, this is a sample program using branches. The screenshots of the ladder program are shown below.
The output of the above program is shown below TIMERS Timer are used in Ladder programming in Rungs and a preset value is fed into it. These are used to delay the proogress from the current rung to the next rung by the preset seconds. A sample program in which timer was used is shown in the figure below. The output of the above program is shown below.
COUNTERS As tha name suggests, counters are used to count. They are mainly employed in industries in which we have to perform counting function.eg. in conveyor belts where the number of goods passing through that conveyor belt are counted. In LADSIM a preset value is fed into the counter after which it is reset. A sample program with output using counter is set and reset position is shown below.
SHIFT REGISTERS Another facility available in LADSIM package is the Shift Register, this function uses a 16 bit word in its operation. There are two type of shift registers in ladsim (BSR) and (BSL). Each time a BSR( bit shift right) is done with bit 15 being replaced by a 0, the binary number is divided by two. If BSL is used (Bit Shift Left), all the bits are shifted left with the LSB being replaced by a zero, the binary value is doubled. The program and its output is shown in the figure below.
Viva Voice Questions Q1) What does resetting a Timer mean? Ans- An ON condition to this function clears all mailbox inputs, outputs, resets all timers to inactive state, and clears all latched relay bits. All integer variables will be cleared to zeros and all string variables will be assigned to empty string. Q2) What advantage does shift register have? Ans- A shift register may be multidimensional, such that its"data in" and stage outputs are themselves bit arrays, this is implemented simply by running several shift registers of the same bit-length in parallel. Shift registers can have both parallel and serial inputs and output. Q3)How can we use shift registers? Ans- In digital circuits, a shift register is a cascade of flip flops, sharing the same clock, in which the output of each flip-flop is connected to the "data" input of the next flip-flop in the chain, resulting in a circuit that shifts by one position the "bit array" stored in it, shifting in the data.
EXPERIMENT NO. 3 Aim: To study the various pneumatic- and actuation and control valves available in the laboratory & develop basic circuits A + A - with start-stop buttons& A + B + A - B - with and without start-stop buttons. Equipment: Pneumatic compressor, direction control valves, PU4 tubes, limiting switch actuators. Theory: Pneumatic and hydraulic systems use directional control valves to direct the flow of fluid through a system. They either completely open or completely closes the devices. Such on/off deices are widely used to develop sequenced control systems. Common type of directional control valve is the spool valves. Another common form of D.C. valve is the poppet valve. This valve is normally in the closed condition, there being no connection between the parts to supply pressure to the system. When the push button is pressed, the ball is pulled out of the seat and flow across the ports. When the button is released, the spring forces the ball back up against its seat and so closes off the flow. There are various ways by which the valves can be actuated, such as: - Push button By pedal By plunges By levers By roller By pneumatic pressure By spring By solenoid Solenoid operated valve is actuated by passing a current through a solenoid. Thus is can be used for electro pneumatic purposes. Circuit Diagrams/Connections:
Figure 1: Circuit for sequence A+A- with Start/Stop switch Figure 2: Circuit for sequence A+B+A-B- with Start/Stop switch
Figure 3: Circuit for sequence A+B+A-B- without Start/Stop switch Procedure: Sequence A+A- With Start/Stop Switch. 1. The pneumatic circuit is connected as shown in the circuit diagram 1. 2. The compressor is turned on so that air supply is turned on to the pneumatic system. 3. Push the button of the push button valve. 4. The air supply is switched off to cylinder A which starts extending. 5. The air is supplied to cylinder A which starts extending. 6. At the end of extension, cylinder s piston handle strikes the limiting switch a +. 7. Limiting switch a + turns on the right side of the valve. 8. Air is then supplied to the other end of cylinder A & it starts compressing. 9. To restart the sequence A+A-, step 3) to 8) are followed again. Sequence A+B+A-B- With Start/Stop Switch. 1. The pneumatic circuit is connected as shown in the circuit diagram 2. 2. Push button is pressed after turning on the compressor. 3. The cylinder A starts extending and actuates limiting switch a +. 4. This switch activates the left position the valve 3 and cylinder B also starts extending. In this way A + B + sequence is obtained. 5. Full extension of cylinder B activates limiting switch b +. This switch activates right position of valves 1 and cylinder A starts compressing.
6. On full compression, limiting switch a - is activated which activates the right portion of valve 3 and cylinder B starts compressing. 7. In this way the sequence A+B+A-B- is completed using push button. 8. To repeat the sequence, push button is pressed again. Sequence A+B+A-B- Without Start/Stop Switch. 1. The pneumatic circuit is connected as shown in the circuit diagram 3. 2. Compressor is turned on. 3. The left position of valve 1 is activated and cylinder A starts extending. 4. Limiting switch a + is activated which activates the left position of valve 2. 5. The cylinder B starts extending and on full extension, switch b + is activated. 6. The right position of the valve 1 activates & cylinder A starts compressing. 7. Switch a - is activated and this activates right position of valve 2. Cylinder B starts compressing and the switch b - is activated, this actuates the left position of the valve 1 again. 8. Thus the sequence A+B+A-B- is continuously repeated. 9. To stop the sequence, compressor is turned off. Result: The sequence A+A- with start-stop buttons & A+B+A-B-with and without start-stop buttons is obtained using pneumatic kit and direction control valves. Precautions: 1. The connecting pipes should not be bent and their length should be minimum. 2. Compressor should have a safety valve and a pressure gauge. 3. PU4 tubes should not be pulled without unlocking the connectors.
Experiment no.- 4 AIM To develop an electro pneumatic circuit of the given sequence A + A - on the electro pneumatic using solenoid operated valves and relay switches. EQUIPMENTS Pneumatic compressors, direction control valves, relay switches, connecting wires, PU4 tubes. THEORY Relays are electrically operated switches in which changing a current in one electric circuit switches a current ON/ in another circuit. Relays are often used in control systems because relays are inductances, they can generate a back voltage when the energising current is switched or when their input switches from a high to low signal. To overcome this problem, a diode is connected across the relay. When the back emf occurs, the diode conducts and shorts it out. Such a diode is termed as free-wheeling or flyback diode. Time-delay relays are control relays that have a delayed switching action. The time delay is usually adjustable and can be initiated when a current flows through the relay coil or when it ceases to flow through the coil. PROCEDURE: 1. Connect the pneumatic circuit as shown. 2. Connect the electrical circuit as shown. 3. The pneumatic compressor and electrical circuit swtich is turned ON. 4. The left side solenoid is activated initially and cylinder starts extending. 5. Limiting switch A + is activated which changes the current in the relay coil. 6. The relay coil then activates the right side solenoid and cylinder starts compressing. 7. The limiting switch A - is activated and the current in relay coil is changed again. 8. Relay coil switch the current to the left side solenoid and the sequence A + A - is repeated again. 9. To turn the system, electrical switch and the pneumatic compressor is turned.
24/11/2014 R2-DC-2 R2-DC-3 R2-DC-4 R2-DC-5 R2-DC-6 R2-DC-7 R2-DC-8 F R1-DC-1 R1-DC-2 R1-DC-3 R1-DC-4 R1-DC-5 R1-DC-6 R1-DC-7 R1-DC-8 R1-AC-1 R1-AC-2 R1-AC-3 R1-AC-4 R1-AC-5 R1-AC-6 R1-AC-7 R1-AC-8 R2-AC-1 R2-AC-2 R2-AC-3 R2-AC-4 R2-AC-5 R2-AC-6 R2-AC-7 R2-AC-8 L1 COM L1 ND L1 NC L2 COM L2 ND L2 NC L4 COM L4 ND L4 NC L3 COM L3 ND L3 NC S1 1 S1 2 S2 1 S2 2 R1 R2 ON
EXPERIMENT NO. 5: AIM: To automate a traffic control unit using LADSIM software. Equipment/Hardware Required: Software Required: Circuits: Networked Computer. LADSIM Software. Make the circuit as shown in the procedure. Procedure: STEP 1 Open ladsim and make the input and output latch as shown in fig.1. Fig.1 STEP 2 Then go to add rung and add 1 rung and then add inputs and timer ( set time 5sec) as shown in fig 2. Fig. 2 STEP 3 Then go to add rung again and add input (T1/DN) and a reset (T1) and add branch and then add latch (OP1) as shown in fig. 3 Fig. 3 STEP 4 Again go to add rung and add the input(op1) and timer (T2-5sec) as done in fig. 4
Fig.4 STEP 5 Then again add rung and add input (T2/DN) and then add unlatch output at the end of rung and then go to add branch and click in between the rung and at the end then go to controls and drag unlatch and put it in the box as shown in the fig and do it for all the things you want to add in the rung. And finally the fig will be like the one as shown in the figure 5 Fig.5 STEP 6 Then again add rung and go to controls and add input (OP2) and put it in start and then timer (T3) at the end and put time-5 sec. Fig. 6 STEP 7 Then again add rung and add input (T3/DN) and the unlatch (OP2) and then add branch in parallel to the unlatch one and put a reset tool for T3 as shown in fig. 7 Fig. 7 STEP 8 Go to simulation on top left of the window and click on either debugger or traffic light. and u will get the window like this
Fig. 8 VIVA VOCE 1) How many timers are available in LADSIM? Ans: There are eight timers available in LADSIM. 2) How many counters are available in LADSIM? Ans: There are eight counters available in LADSIM. 3) How many flags are there in a LADSIM? Ans: There are sixteen flags in a LADSIM. 4) How many inputs and outputs are in LADSIM? Ans: There are twelve inputs and outputs in LADSIM.
EXPERIMENT NO.-6 AIM- To program a vinytics make PLC through keypad and develop basic programs to demonstrate use of inputs, outputs, AND & OR. EQUIPMENT/HARDWARE REQUIRED- Vinytics make modular PLC, keypad and UPS. THEORY- A programmable logic controller, PLC or programmable controller is a digital computer used for automation of typically industrial electromechanical processes, such as control of machinery on factory assembly lines, amusement rides, or light fixtures. PLCs are used in many industries and machines. PLCs are designed for multiple analogue and digital inputs and output arrangements, extended temperature ranges, immunity to electrical noise, and resistance to vibration and impact. Programs to control machine operation are typically stored in batterybacked-up or non-volatile memory. A PLC is an example of a "hard" real-time system since output results must be produced in response to input conditions within a limited time, otherwise unintended operation will result. COMMAND DESCRIPTION The VMC-PLCT has 28 keys and six seven segment displays to communicate with the outside world. As VMC-PLCT is switched ON, a message PLC 51 is displayed on the display and all the keys are in command mode. The keyboard is shown below.
Keyboard description RESET- resets the system SHIFT- provides a second level command to all keys CHK (check)- checks the status of output of only higher stage and if it is lower stage it goes to next line. GOTO- unconditional jump to levels CNT- counter ANI- AND inverse RST- reset the input. LD- inputs SER(serial command)- for RS232C communication with PC END- end the program TIM- timer EXEC- for execution COUNT- to set the delays or number of counts in timer and counter SET- to set the input/output. Once the output is set, it remains high until it is reset LDI- load inverse OUT- output ORI- OR inverse PRE(previous)- previous is used as a immediate terminator in case of exam memory
NEXT- increments the program counter ORB- OR block EXAM(examine memory)- allows user to examine instructions SEC- second IL(interlock)- to interlock the execution after any particular command ILC(interlock clear)- to clear interlock for further execution EN(enable counter)- to enable the counter BLANK- this key is used for execution of a command BM(block move)- allows user to move a block form monitor to RAM area OR- logical OR AND- logical AND 0 to 9- numeric keys If instead of a valid command the user gives a data, then system will display -err. SAMPLE PROGRAMS UNDERSTANDING PROCEDURE OF WRITING PROGRAM LOGICS Input (either high or low) are given at the input ports (X00-X07 and X10-X17) and the output is obtained at the ports (Y20-Y27 and Y30-Y37). Here X00 controls the output port Y20. Example 1 Implement the following ladder network using PLC. X00 Y20 PROGRAM LD 00 NEXT OUT 20 NEXT
END NEXT BLANK BLANK NEXT EXECUTE Now, when PLC is connected to the power supply and a +5V is given to the 00 port the corresponding output port 20 also goes high and the LED glows LOGIC X00 Y20 H H L L Example 2 Implement the following ladder network using PLC X00 Y20 X01 Y21 Program LD 00 NEXT OUT 20 NEXT LDI 01 NEXT OUT 21 NEXT END NEXT BLANK BLANK NEXT EXECUTE LOGIC X00 Y20 X01 Y21 ON ON ON ON Example 3 Implement the following ladder network using PLC X00 X01 Y20 X00 X02 Y21 Program LD OO NEXT AND 01 NEXT OUT 20 NEXT
LD 00 NEXT ANI 02 NEXT OUT 21 NEXT END NEXT BLANK BLANK NEXT EXECUTE LOGIC X00 X01 X02 Y20 Y21 ON ON ON ON ON ON ON ON ON ON Example 4 Implement the following network X01 X00 Y20 X01 Y21 X02 Program LD 00 NEXT OR 01 NEXT OUT 20 NEXT LD 01 NEXT ORI 02 NEXT OUT 21 NEXT END NEXT BLANK BLANK NEXT EXECUTE LOGIC X00 X01 Y20 X01 X02 Y21 0 0 1 1 0 1 0 1 0 1 1 1 0 1 0 1 0 0 1 1 1 1 0 1 Example 5
Implement the following network X00 X02 Y20 Program LD 00 NEXT X01 X03 OR 01 NEXT LD 02 NEXT OR 03 NEXT ANB NEXT OUT 20 NEXT END NEXT BLANK BLANK NEXT EXECUTE LOGIC Example 6 Implement the network using PLC X00 X01 X02 X03 Y20 0 0 0 0 0 0 0 0 1 0 0 0 1 0 0 0 0 1 1 0 0 1 0 0 0 0 1 0 1 1 0 1 1 0 1 0 1 1 1 1 1 0 0 0 0 1 0 0 1 1 1 0 1 0 1 1 0 1 1 1 1 1 0 0 0 1 1 0 1 1 1 1 1 0 1 1 1 1 1 ORB 1 X00 X02 Y20 following ladder Program X01 X03 LD 00 NEXT AND 02 NEXT LD 01 NEXT AND 03 NEXT ORB NEXT OUT 20 NEXT END NEXT BLANK BLANK NEXT EXECUTE
LOGIC X00 X01 X02 X03 Y20 ON ON ON ON ON ON ON ON ON Program 7 LD 00 NEXT SET 20 NEXT LD 01 NEXT RST 20 NEXT END NEXT BLANK BLANK NEXT EXECUTE LOGIC X00 X01 Y20 ON ON ON Program 8 LD 00 NEXT TIM 60 NEXT # 50 NEXT LD 60 NEXT OUT 20 NEXT END NEXT BLANK BLANK NEXT EXECUTE LOGIC X00 TIM60 Y20 ON ON (after 5 sec) ON