Explain UP counter instruction of PLC with suitable instruction.

Explain UP counter instruction of PLC with suitable instruction.
by

1 Answer

Answer :

The CTU is an instruction that counts false-to-true rung transitions. Rung transitions can be caused by events occurring in the program. When rung conditions for a CTU instruction have made a false-to-true transition, the accumulated value is incremented by one count, provided that the rung containing the CTU instruction is evaluated between these transitions. 

image

The accumulated value is retained when the rung conditions again become false. The accumulated count is retained until cleared by a reset (RES) instruction that has the same address as the counter reset. The control word for counter instructions includes six status bits, as indicated below

image

• CU Bit: This status bit is true when UP counter instruction is true. 

• DN bit: This bit is true when accumulated value is equal to or greater than the present value of the counter. 

• OV(Overflow) bit: when counter count value exceeds 32,767,this bit becomes true. 

• UN(Underflow):It will go true when counter counts below -32,768. 

• Accumulator Value (ACC): This is the number of false-to-true transitions that have occurred since the counter was last reset. 

• Preset Value (PRE): Specifies the value which the counter must reach before the controller sets the done bit.

In the following example count up counter is used to control the Red and Green lamps. Operating pushbutton I:2/3 provides the off-to-on transition pulses that are counted by the counter. The preset value of the counter is set for 7. Each false-to-true transition of rung 1 increases the counter’s accumulated value by 1. After 7 pulses, or counts, when the preset counter value equals the accumulated counter value, output DN is energized. As a result, rung 2 becomes true and energizes output O:5/1 to switch the red pilot light on. At the same time, rung 3 becomes false and de-energizes output O:5/2 to switch the green pilot light off. The counter is reset by closing pushbutton I:2/1, which makes rung 4 true and resets the accumulated count to zero. Counting can resume when rung 4 goes false again.

image

image

by

Related questions

State the function of PLC memory w.r.t. types, speed of execution.

Description : State the function of PLC memory w.r.t. types, speed of execution.

Last Answer : PLC memory cab be divided into two major types: 1) System memory: a) Executive Memory: The executive is a permanently stored collection of programs that are considered part of the system itself. ... RAM memory is fastest amongst all type of memory. Flash ROM memory is faster than ROM memory. 

State the function of seal in circuit w.r.t. PLC.

Description : State the function of seal in circuit w.r.t. PLC.

Last Answer : Standard Start-Stop-Seal circuit:  * The Start-Stop-Seal circuit is as shown in figure. The power circuit consists of 3ph load (Motor) connected by a main contactor (M) to 3-phase supply. The ... * When STOP is pressed, M gets de-energized and motor gets disconnected from supply.

Draw the block diagram of PLC.

Description : Draw the block diagram of PLC.

Last Answer : Block diagram of PLC and input/output devices used for PLC Input/output devices - The input module has bank of terminals for physically connecting input devices, like push buttons, limit switches etc. ... is to translate signals from the PLC's CPU into a form that the output device can use.

Draw a block diagram of digital output module of PLC.

Description : Draw a block diagram of digital output module of PLC.

Last Answer : Block diagram of digital output module of PLC:

List any two advantages and any two disadvantages of PLC.

Description : List any two advantages and any two disadvantages of PLC.

Last Answer : Advantages of PLC: i) Increased productivity ii) Increased product quality iii) Increased flexibility and convertibility iv) Reduced manpower v) Reduced cost of product vi) Better inventory control vii) Increased ... v) PLCs are not very good at handling large amount of data, or complex data.

State any two input and output devices of PLC

Description : State any two input and output devices of PLC

Last Answer : Input Devices of PLC: i) Selector switches ii) Push buttons iii) Binary encoders iv) Mechanical/magnetic Limit switches v) Inductive/ capacitive/optical proximity switches vi) Analog transducers ... /Lamps v) Solenoids vi) Continuous/ discrete valves vii)Analog/digital indicators/recorders etc.

Explain count up (CTU) instruction with timing diagram.

Description : Explain count up (CTU) instruction with timing diagram.

Last Answer : The CTU is an instruction that counts false-to-true rung transitions. Rung transitions can be caused by events occurring in the program. When rung conditions for a CTU instruction have made a false-to-true ... of Counter up(CTU) Instruction: Too many uploads - please try again in an hour

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

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

Which of the following registers is used to keep track of address of the memory location where the next instruction is located? A) Memory address register B) Memory data register C) Instruction register D) Program counter

Description : Which of the following registers is used to keep track of address of the memory location where the next instruction is located? A) Memory address register B) Memory data register C) Instruction register D) Program counter

Last Answer : Answer : D

Which of the following registers is loaded with the contents of the memory location pointed by the PC? A) Memory address registers B) Memory data registers C) Instruction register D) Program counter

Description : Which of the following registers is loaded with the contents of the memory location pointed by the PC? A) Memory address registers B) Memory data registers C) Instruction register D) Program counter

Last Answer : Answer : C

The ___________ contains the address of the next instruction to be executed. a) IR b) PC c) Accumulator d) System counter

Description : The ___________ contains the address of the next instruction to be executed. a) IR b) PC c) Accumulator d) System counter

Last Answer : Answer: b Explanation: PC stands for program counter (It contains the address of the next instruction to be executed)

Content of the program counter is added to the address part of the instruction in order to obtain the effective address is called_______ A. relative address mode. B. index addressing mode. C. register mode. D. implied mode.

Description : Content of the program counter is added to the address part of the instruction in order to obtain the effective address is called_______ A. relative address mode. B. index addressing mode. C. register mode. D. implied mode.

Last Answer : A. relative address mode.

The load instruction is mostly used to designate a transfer from memory to a processor register known as_________ A. Accumulator B. Instruction Register C. Program counter D. Memory address Register

Description : The load instruction is mostly used to designate a transfer from memory to a processor register known as_________ A. Accumulator B. Instruction Register C. Program counter D. Memory address Register

Last Answer : A. Accumulator

The instruction fetch operation is initiated by loading the contents of program counter into the and sends _ request to memory: a. Memory register and read b. Memory register and write c. Data register and read d. Address register and read

Description : The instruction fetch operation is initiated by loading the contents of program counter into the and sends _ request to memory: a. Memory register and read b. Memory register and write c. Data register and read d. Address register and read

Last Answer : d. Address register and read

The contents of the program counter isthe __——__—oof the instruction to be run. a. Data b. Address c. Counter d. None of these

Description : The contents of the program counter isthe __——__—oof the instruction to be run. a. Data b. Address c. Counter d. None of these

Last Answer : b. Address

The instruction read from memory is then placed in the ___and contents of program counter is __ so that it contains the address of_ __ instruction in the program. a. Program counter, incremented and next b. Instruction register, incremented and previous c. Instruction register, incremented and next d. Address register, decremented and next

Description : The instruction read from memory is then placed in the ___and contents of program counter is __ so that it contains the address of_ __ instruction in the program. a. Program counter, ... incremented and previous c. Instruction register, incremented and next d. Address register, decremented and next

Last Answer : c. Instruction register, incremented and next

When subroutine is called contents of program counter is location address of __ instruction following call instruction is stored on _ __and program execution is transferred to __ address. a. Non executable, pointer and subroutine b. Executable, Stack and Main program Cc. Executable, Queue and Subroutine d. Executable, Stack and Subroutine

Description : When subroutine is called contents of program counter is location address of __ instruction following call instruction is stored on _ __and program execution is transferred to __ address. a. Non ... , Stack and Main program Cc. Executable, Queue and Subroutine d. Executable, Stack and Subroutine

Last Answer : d. Executable, Stack and Subroutine

Who change the address in the program counter and cause the flow of control to be altered: a Shift manipulation b. Circular manipulation c. Program control instruction d. __ Allof these

Description : Who change the address in the program counter and cause the flow of control to be altered: a Shift manipulation b. Circular manipulation c. Program control instruction d. __ Allof these

Last Answer : c. Program control instruction

Which of the following registers is used to keep track of address of the memory location where the next instruction is located? a. Memory address register b. Memory data register c. Instruction register d. Program counter

Description : Which of the following registers is used to keep track of address of the memory location where the next instruction is located? a. Memory address register b. Memory data register c. Instruction register d. Program counter

Last Answer : Program counter

Which of the following registers is loaded with the contents of the memory location pointed by the PC? a. Memory address registers b. Memory data registers c. Instruction register d. Program counter

Description : Which of the following registers is loaded with the contents of the memory location pointed by the PC? a. Memory address registers b. Memory data registers c. Instruction register d. Program counter

Last Answer : Instruction register

The register which keeps track of the execution of a program and which contains the memory address of the instruction currently being executed is known as: a) Index Register b) Memory Address Register c) Program Counter d) None of The Above

Description : The register which keeps track of the execution of a program and which contains the memory address of the instruction currently being executed is known as: a) Index Register b) Memory Address Register c) Program Counter d) None of The Above

Last Answer : c) Program Counter

In microprocessor the next instruction to be executed is stored in a) Program Counter b) Stack Pointer c) Memory Pointer d) Accumulator

Description : In microprocessor the next instruction to be executed is stored in a) Program Counter b) Stack Pointer c) Memory Pointer d) Accumulator

Last Answer : Ans: Program Counter

When the RET instruction at the end of subroutine is executed, a. the information where the stack is iniatialized is transferred to the stack pointer b. the memory address of the RET instruction is transferred to the program counter c. two data bytes stored in the top two locations of the stack are transferred to the program counter d. two data bytes stored in the top two locations of the stack are transferred to the stack pointer

Description : When the RET instruction at the end of subroutine is executed, a. the information where the stack is iniatialized is transferred to the stack pointer b. the memory address of the RET instruction is ... two data bytes stored in the top two locations of the stack are transferred to the stack pointer

Last Answer : c. two data bytes stored in the top two locations of the stack are transferred to the program counter

When a subroutine is called, the address of the instruction following the CALL instructions stored in/on the a. stack pointer b. accumulator c. program counter d. stack

Description : When a subroutine is called, the address of the instruction following the CALL instructions stored in/on the a. stack pointer b. accumulator c. program counter d. stack

Last Answer : d. stack

Which of the following registers is used to keep track of address of the memory location where the next instruction is located? a. Memory address register b. Memory data register c. Instruction register d. Program counter

Description : Which of the following registers is used to keep track of address of the memory location where the next instruction is located? a. Memory address register b. Memory data register c. Instruction register d. Program counter

Last Answer : d. Program counter

Which of the following registers is loaded with the contents of the memory location pointed by the PC? a. Memory address register b. Memory data register c. Instruction registers d. Program counter

Description : Which of the following registers is loaded with the contents of the memory location pointed by the PC? a. Memory address register b. Memory data register c. Instruction registers d. Program counter

Last Answer : c. Instruction registers

Which of the following registers is used to keep track of address of the memory location where the next instruction is located? a. Memory address register b. Memory data register c. Instruction register d. Program counter

Description : Which of the following registers is used to keep track of address of the memory location where the next instruction is located? a. Memory address register b. Memory data register c. Instruction register d. Program counter

Last Answer : d. Program counter

Which of the following registers is loaded with the contents of the memory location pointed by the PC? a. Memory address registers b. Memory data registers c. Instruction register d. Program counter

Description : Which of the following registers is loaded with the contents of the memory location pointed by the PC? a. Memory address registers b. Memory data registers c. Instruction register d. Program counter

Last Answer : c. Instruction register

The subprogram finish the return instruction recovers the return address from the: a. Queue b. Stack c. Program counter d. Pointer

Description : The subprogram finish the return instruction recovers the return address from the: a. Queue b. Stack c. Program counter d. Pointer

Last Answer : b. Stack

IR stands for: a. Intel register b. In counter register c. Index register d. Instruction register

Description : IR stands for: a. Intel register b. In counter register c. Index register d. Instruction register

Last Answer : d. Instruction register

Which of the following registers is used to keep track of address of the memory location where the next instruction is located? a. Memory address register b. Memory data register c. Instruction register d. Program counter

Description : Which of the following registers is used to keep track of address of the memory location where the next instruction is located? a. Memory address register b. Memory data register c. Instruction register d. Program counter

Last Answer : d. Program counter

Which of the following registers is loaded with the contents of the memory location pointed by the PC? a. Memory address register b. Memory data register c. Instruction registers d. Program counter

Description : Which of the following registers is loaded with the contents of the memory location pointed by the PC? a. Memory address register b. Memory data register c. Instruction registers d. Program counter

Last Answer : c. Instruction registers

Explain pressure actuated switch with neat constructional diagram.

Description : Explain pressure actuated switch with neat constructional diagram.

Last Answer : Pressure actuated switch: A pressure actuated switch is a device designed to monitor a process pressure and provide an output when a set pressure (setpoint) is reached. A pressure actuated switch does this by ... range spring (e.g. if the nt is turned clockwise the trip pressure will be higher). 

List types of memory. Explain any one type of memory in brief.

Description : List types of memory. Explain any one type of memory in brief.

Last Answer : Types of Memories in PLC:  i) Executive Memory  ii) Scratch Pad Memory  iii) Data Table a) Input image memory b) Output image Memory c) Internal bits/ registers/ words  ... storage for programmed instructions entered by the user. The user program area also stores the control program.

Draw power and control circuit for definite time-limit starter for slip-ring induction motor. Explain its working.

Description : Draw power and control circuit for definite time-limit starter for slip-ring induction motor. Explain its working.

Last Answer : Definite Time-limit Starter for Slip-ring Induction Motor: This starter is used for automatic control of acceleration of slip-ring induction motor at the time of starting. In this starter, the ... each phase, shorting the rotor winding terminals and final acceleration of the motor takes place. 

Explain concept of capacitive type proximity switch with neat schematic diagram.

Description : Explain concept of capacitive type proximity switch with neat schematic diagram.

Last Answer : Capacitive type proximity switch: A capacitive proximity switch is device that senses presence of metallic or nonmetallic objects. The internal circuit consists of an oscillator, threshold detection stage and ... in oscillation amplitude is detected and output switching device is turned on. 

Write the ladder program for 24 hour clock.

Description : Write the ladder program for 24 hour clock.

Last Answer : Ladder Program for 24 hour clock:

Develop the control circuit for star-delta starter used for starting a 3 ∅ induction motor.

Description : Develop the control circuit for star-delta starter used for starting a 3 ∅ induction motor.

Last Answer : Control Circuit for Star-Delta Starter: 1) Automatic Star-Delta Starter: OR 2) Semi- automatic Star-Delta Starter:

Give the full form of SCADA & HMI.

Description : Give the full form of SCADA & HMI.

Last Answer : Full Form of SCADA and HMI:  SCADA:-Supervisory Control and Data Acquisition  HMI :- Human Machine Interface

List types of timers.

Description : List types of timers.

Last Answer : Types of Timers: Retentive Timers: 1. ON Delay 2. OFF Delay Non Retentive Timers: 1. ON Delay 2. OFF Delay

State the need of automation.

Description : State the need of automation. 

Last Answer : Need of Automation in Process : * To fulfill the demand of product at right time. * To reduce the human errors and involvement of human being in the process. * For better productivity. * For better ... of process. * For better quality. * For reducing man power. * For reducing cost of product.

Draw block diagram of PID controller

Description : Draw block diagram of PID controller

Last Answer : Block diagram of PID Controller:

Develop power and control diagram for secondary frequency acceleration starter of slip ring induction motor.

Description : Develop power and control diagram for secondary frequency acceleration starter of slip ring induction motor. 

Last Answer : Power and Control Circuit diagram for secondary frequency acceleration starter of slip ring induction motor:

Differentiate between two-wire and three-wire control

Description : Differentiate between two-wire and three-wire control

Last Answer : Two-Wire Control  Three-Wire Control 1 The control component offers only two-wires for its connection in control circuit. The control components offer threewires for their connection in control ... using starter. The safe starting ensures the Novolt protection.  4

Differentiate between power and control wiring

Description : Differentiate between power and control wiring

Last Answer : Power wiring Control wiring 1 Used for connecting load to main power supply through appropriate switchgear and protecting devices such as overload relay contacts Used for ... can be used for connecting control circuit as control circuit does not carry higher current.

Draw construction of DC servomotor.

Description : Draw construction of DC servomotor. 

Last Answer : DC servomotor:

List any four names of optial sensors

Description : List any four names of optial sensors

Last Answer : Optial sensors: i) Photodiodes ii) Phototransistors iii) LDRs iv) Photovoltaic cells v) Optical encoder vi) Scintillation counter vii) Photoionization detector viii) Photographic plates

List any two ratings of digital input and digital output module each.

Description : List any two ratings of digital input and digital output module each.

Last Answer : Ratings of Digital Input Module: i) Rated voltage & current: +24V DC at 4mA/120V AC at 6mA/230V AC at 9mA ii) Specified operational voltage range: 0-30V DC/ 264V AC. iii) Absolute maximum input voltage: + ... / 2A for relay type/0.5A AC vi) Rated current/common: 6A DC/8A for relay type/0.5A AC

Draw block diagram of proportional controller.

Description : Draw block diagram of proportional controller.

Last Answer : Block diagram of Proportional Controller:

List applications of servomotor.

Description : List applications of servomotor.

Last Answer : Applications of Servomotor: 1) Computers 2) Robotics and toys 3) CD/DVD players 4) Textile industries 5) Instrument servos 6) Tracking and guidance system 7) Self-balancing recorders 8 ... 9) Process controllers 10) Electromechanical actuators 11) Air-craft control system 12) Programming device