Explain the role of watch dog timer in programmable logic controller.

1 Answer

Answer :

Watch dog timer is a type of timer used to protect maloperation of PLC. It independently works( starts counting internal clock pulses) each time when PLC starts its execution. User program must reset the timer some where in the program. If the user program stops working because of some fault or some unknown condition, then watch dog timer overflows and generates nonmaskable interrupt to reset PLC.

Related questions

Description : Interfacing devices for DMA controller, programmable interval timer are respectively…a) 8257, 8253 b) 8253, 8257 c) 8257,8251 d)8251,825721.

Last Answer : a) 8257, 8253

Description : Explain how a Programmable Logic Controller (PLC) is different from an ordinary personal computer. Also write the advantages and disadvantages of PLC.

Last Answer : PLC PC 1 It has embedded processor with limited computing power It has a CPU with high computing power  2 Design of PLC is for reliable operation in industrial ... 3) Use of PLCs may be restricted in some high heat, vibration environment not suitable for electronic circuit

Description : What forma programmable logic controller training is available in Oklahoma City?

Last Answer : Yes, there are formal classroom courses available in Oklahoma City about programmable logic controllers(PLC). You can enroll in Vatterott College which has an outstanding PLC program. They offer a ... Organization of PLC, and many other crucial areas of knowledge to complete your PLC training.

Description : Blackt Electrotech 230V 24x7 Energy Saving Socket Type Digital Programmable Plastic Electronic Timer (White)

Last Answer : Buy from amazon: https://amzn.to/2SUTSdv Buy: http://bit.ly/2ZqlAkS

Description : 8086 microprocessor is interfaced to 8253 a programmable interval timer. The maximum number by which the clock frequency on one of the timers is divided by a) 216 b) 28 c) 210 d) 220

Last Answer : d) 220

Description : List & explain the timer instruction of PLC. Draw the ladder diagram to verify (i) OR gate& (ii) NOR gate logic 

Last Answer : Depending on the time delay and operation, there are two types of timers  * PLC timer- (i) ON delay timer  (ii) OFF delay timer Description (i) ON delay timer 1) This instruction counts time interval when ... a) OR gate ladder diagram y = A + B b)NOR gate ladder diagram

Description : Explain with block diagram the working of programmable logic control system. (PLC).

Last Answer : Programmable logic controller:  Block diagram: OR Explanation: PLCs are industrially hardened microcomputers that perform discrete or continuous control functions in a variety ... provides an interface between the PLC and user during program development, start-up and trouble shooting

Description : The Intel 8259 is a - chip programmable interrupt controller  1. Single 2. Double 3. Triple 4. All of the above 

Last Answer : The Intel 8259 is a - chip programmable interrupt controller Single 

Description : In CNC systems multiple microprocessors and programmable logic controllers work a.in parallel b.in series c.one after the other d.for 80% of the total machining time

Last Answer : a.in parallel

Description : Rules of FSM are encoded in. a. ROM b. Random logic c. Programmable logic array d. Allof these

Last Answer : d. Allof these

Description : Full form of PLA in CU: a. Progrmmable Logic Array b. Programs Load Array c. Programmable Logic Accumulator d. all of these

Last Answer : a. Progrmmable Logic Array

Description : What is field programmable logic array?

Last Answer : The second type of PLA is called a field programmable logic array. The user by means of certain recommended procedures can program the EPLA.

Description : What is programmable logic array? How it differs from ROM?

Last Answer : In some cases the number of don’t care conditions is excessive, it is more economical to use a second type of LSI component called a PLA. A PLA is similar to a ROM in concept; however it does not provide full decoding of the variables and does not generates all the min-terms as in the ROM.

Description : What is programmable logic array? How it differs from ROM?

Last Answer : In some cases the number of don’t care conditions is excessive, it is more economical to use a second type of LSI component called a PLA. A PLA is similar to a ROM in concept; however it does not provide full decoding of the variables and does not generates all the min-terms as in the ROM.

Description : List basic types of programmable logic devices.

Last Answer : 1. . Read only memory 2. . Programmable logic Array 3. . Programmable Array Logic

Description : Draw the block diagram of Programmable Logic Array.

Last Answer : block diagram of Programmable Logic Array

Description : Complex Programmable Logic Devices (CPLD)

Last Answer : Complex Programmable Logic Devices (CPLD) CPLDs are the collection of SPLD structures which are interconnected via multiplexer or switch matrix. CPLD consists of number of logic blocks or ... timing characteristics. CPLD are use in cost sensitive application and it have low power usage.

Description : Simple Programmable Logic Devices 

Last Answer : Simple Programmable Logic Devices (SPLD) There are three main types of SPLD architecture Programmable Logic Array (PLA), Programmable Array Logic (PAL) and Generic Array Logic (GAL). SPLD is made ... ). PAL can not be reconfigured. GAL uses EEPROM configuration so it can be reconfigured.

Description : What is programmable logic device?

Last Answer : Programmable Logic Devices (PLD) PLD chips can be erased electrically and program to implement different logic function. Designing with PLD chips is faster which  ... Logic (GAL). FPGA and CLPD are the types of advanced PLDs.

Description : Draw and explain the block diagram of fuzzy logic controller.

Last Answer : Ans:  OR 1 Fuzzification: It is the action of transforming a given state as crisp input into fuzzy values by evaluating membership function for purpose to be used by a ... at producing a non- fuzzy control action that best represent the possibility of an inferred fuzzy control action

Description : Draw and explain Fuzzy logic controller. 

Last Answer : Explanation:-- Fuzzification: It is the action of transforming a given state as crisp input into fuzzy values by evaluating membership function for purpose to be used by a fuzzy ... a non- fuzzy control action that best represent the possibility of an inferred fuzzy control action

Description : An aspect of Input/Output controller of data logic is called (1) General Buffering (2) Zero Buffering (3) Buffering (4) Data Buffering

Last Answer : Buffering

Description : Explain ON delay timer and OFF delay timer of PLC.

Last Answer : On delay timer operates such that when rung containing timer is true, the timer starts counting time ticks. At the end of timer preset time period, output is made active. The off- ... is an operation to turn OFF output when preset time expires after a predetermined input is given.

Description : In an emergency, the fastest way to interrupt power and stop the winch shown in the illustration is for the ____________. EL-0102 A. mate to open the disconnect switch at 'L1' and 'L2' B. ... watch engineer to open the winch circuit breaker D. electrician to open the test link at the controller

Last Answer : Answer: B

Description : If you hear a loud buzzing noise coming from a magnetic motor controller, you should ____________. A. assume that the motor is operating at a full load B. assume that the controller is operating normally C. ... of the problem D. feel the outside of the casing with your hand to see if it is hot

Last Answer : Answer: C

Description : What is watchdog timer ? Explain the implementation of time out for ATM with block diagram and program.

Last Answer : A special type of timer is a watchdog timer, which will reset the system after a predefined timeout. Watchdog timer reset timer every X time unit, else timer generates a signal ... be loaded into timereg. This is to prevent erroneous software from unintentionally resetting the watchdog timer.

Description : Explain the offset in proportional controller.

Last Answer : Offset is a sustained error that cannot be eliminated by proportional control alone The basic equation of proportional control is as follows:  CO (t) = Kp e(t) + CO (0) Where CO(t) ... will not change and it will cause permanent change in error and this is offset error in proportional control

Description : What is a watchdog timer in Arduino?

Last Answer : A watchdog timer in Arduino is a timer that can be used to monitor the state of the microcontroller and reset the system if it becomes unresponsive or crashes.

Description : What is a watchdog timer in Arduino?

Last Answer : A watchdog timer in Arduino is a hardware timer that can be used to reset the microcontroller if the program stops running or crashes.

Description : What is a watchdog timer in Arduino?

Last Answer : A watchdog timer in Arduino is a hardware timer that can be used to reset the microcontroller if the program stops running or crashes.

Description : What is a watchdog timer in Arduino?

Last Answer : A watchdog timer in Arduino is a hardware timer that can be used to reset the microcontroller if the program stops running or crashes.

Description : Have you ever tried the timer function on your kitchen oven?

Last Answer : I would guess a lot of ovens are different but with ours you just push timer then hold the time button for the amount of time you wish,once you let go it will start counting down then beep letting you know the time is up.

Description : What service should I use for filing taxes? (first timer)

Last Answer : answer:With as simple a return as you appear to have, that is, with no mortgage or student loan or other deductible interest (is student loan interest even tax deductible?) and no other extraordinary income or ... - not one iota - for your cat. But I hope you enjoy its company. See, I care!

Description : Why is my Blackberry continually showing a moving "timer" symbol every time I try to do something on it?

Last Answer : Have you tried to remove the battery and reset it? It could be the internet supplier or your internet connections on it. However, I am no whiz either. So there, I gave it a bash. It sounds to me like the net connection is timing out.

Description : What are the "must-do's" in New York City for a first-timer?

Last Answer : answer:Make sure you hit up some of the museums. The Natural History museum in Manhattan is my favorite place on earth. http://en.wikipedia.org/wiki/American_Museum_of_Natural_History

Description : Do you ever wish that life worked on your timer instead of you having to live according to it?

Last Answer : I would like to live on a 27 hour day. 9 hours of sleep and 18 awake would suit me perfectly.

Description : Does the latest ipod shuffle have a sleep timer (or shut off after a certain amount of time)?

Last Answer : Unfortunately, no. As there’s no display and no way to access any kind of settings, there’s no documented way for activating a sleep timer on the Shuffle.

Description : I need a timer vault, any advice?

Last Answer : Why is kinky a tag? Don’t put a woman in a timed vault. Especially don’t put a woman in a small vault… I try not to judge, but I’m pretty sure that 200 hours in a vault will kill her from lack of oxygen…

Description : How can I reset the clock in this (C++) timer function?

Last Answer : I don’t know C++ very well but “bool reset = false;” sounds like it shouldn’t be included

Description : Has anyone ever created a timer using JavaScript?

Last Answer : answer:I think the easiest thing to do is just use an existing timer that uses 1,2,3,4 syntax and convert it to hh:mm:ss yourself. It should be a fairly straightforward conversion. You're basically just ... (I imagine there are also some existing conversions you can find, but I'd say just dive in).

Description : I need a timer...

Last Answer : Are you talking about Jeopardy style switch?

Description : Have you as a Fluther "Old-Timer" been properly thanked?

Last Answer : Yes…your hospitality is greatly appreciated, Flutherite-who-was-here-before-me!

Description : How to reset cellphone call timer?

Last Answer : If you never tampered with the code default should be 12345

Description : How to make or buy an animated timer graphic for use in video?

Last Answer : The best timers out there are probably made in Flash. If you happen to have the program, you can learn how to make one in Flash here, then import the video to Flash and apply it over the ... all that, there are some you can download. Googling Flash Countdown Timers brings up some good results.

Description : Has anyone ever been to South Africa, and if so do you have any tips for a first timer?

Last Answer : Shrubbery is there now for a month. You can send her a PM and ask since she most likely won’t see this question.

Description : What would be a good blogging topic for a first-timer?

Last Answer : answer:Everyone I know seems to start a blog when traveling overseas. My favorite of these was by the friend who went to a different Parisian cafe every day and reviewed it (http://www.undergroundparis. ... seems a bit too common, unless you can give it some kind of interesting, even quirky, spin.

Description : You want to boil a two-minute egg. If you only have a three-minute timer (hourglass), a four-minute timer and a five-minute timer, how can you boil the egg for only two minutes? -Riddles

Last Answer : Once the water is boiling, turn the three-minute timer and five-minute timer over. When the three-minute timer runs out, put the egg in the boiling water. When the five-minute timer runs out, two minutes ... time take the egg out of the water. You don't need the four-minute timer for this riddle.

Last Answer : that Timer Of current With the help Let's go Him Electric Timer Says.

Last Answer : Time Of words Money Time , time Section Controlled Switch Timer Says. Timer Mainly Two Type E.g. 1 . Electric Timer , II . Mechanical Timer.