Programmable Logic Controllers
Programmable Logic Controllers
5th Edition
ISBN: 9780073373843
Author: Frank D. Petruzella
Publisher: McGraw-Hill Education
Expert Solution & Answer
Book Icon
Chapter 2, Problem 39RQ

Explanation of Solution

a.

Conversion of power supply:

  • Generally, the processor section, memory section and an I/O module requires a DC voltage of 5VDC.
  • When these sections of modules are plugged int...

Explanation of Solution

b.

Hold-up time:

  • When the power is dismissed suddenly, it can cause damage to PLC or sometimes, it can even completely hold the process control operation abruptly.
  • To avoid this situation, PLC must be able to hold up the time...

Blurred answer
Students have asked these similar questions
Whentheuserenters!!,themostrecentcommandinthehistoryisexecuted.In the example above, if the user entered the command: Osh> !! The ‘ls -l’ command should be executed and echoed on user’s screen. The command should also be placed in the history buffer as the next command. Whentheuserentersasingle!followedbyanintegerN,theNthcommandin the history is executed. In the example above, if the user entered the command: Osh> ! 3 The ‘ps’ command should be executed and echoed on the user’s screen. The command should also be placed in the history buffer as the next command. Error handling: The program should also manage basic error handling. For example, if there are no commands in the history, entering !! should result in a message “No commands in history.” Also, if there is no command corresponding to the number entered with the single !, the program should output "No such command in history."
Activity No. Activity Time (weeks) Immediate Predecessors 1 Requirements collection 3 2 Requirements structuring 4 1 3 Process analysis 3 2 4 Data analysis 3 2 5 Logical design 50 3,4 6 Physical design 5 5 7 Implementation 6 6 c. Using the information from part b, prepare a network diagram. Identify the critical path.
2. UNIX Shell and History Feature [20 points] This question consists of designing a C program to serve as a shell interface that accepts user commands and then executes each command in a separate process. A shell interface gives the user a prompt, after which the next command is entered. The example below illustrates the prompt osh> and the user's next command: cat prog.c. The UNIX/Linux cat command displays the contents of the file prog.c on the terminal using the UNIX/Linux cat command and your program needs to do the same. osh> cat prog.c The above can be achieved by running your shell interface as a parent process. Every time a command is entered, you create a child process by using fork(), which then executes the user's command using one of the system calls in the exec() family (as described in Chapter 3). A C program that provides the general operations of a command-line shell can be seen below. #include #include #define MAX LINE 80 /* The maximum length command */ { int…

Chapter 2 Solutions

Programmable Logic Controllers

Ch. 2 - Prob. 11RQCh. 2 - What are the advantage and the disadvantage of...Ch. 2 - With reference to PLC discrete input modules: a....Ch. 2 - Prob. 14RQCh. 2 - Explain the function of the backplane of a PLC...Ch. 2 - Prob. 16RQCh. 2 - Prob. 17RQCh. 2 - Prob. 18RQCh. 2 - What electronic element can be used as the...Ch. 2 - With reference to discrete output module current...Ch. 2 - What electronic element can be used as the...Ch. 2 - Prob. 22RQCh. 2 - Prob. 23RQCh. 2 - Prob. 24RQCh. 2 - Prob. 25RQCh. 2 - Prob. 26RQCh. 2 - Prob. 27RQCh. 2 - Prob. 28RQCh. 2 - Prob. 29RQCh. 2 - Explain the difference between a unipolar and...Ch. 2 - Prob. 31RQCh. 2 - In what two ways can the loop power for current...Ch. 2 - Prob. 33RQCh. 2 - Prob. 34RQCh. 2 - Prob. 35RQCh. 2 - Write a short explanation for each of the...Ch. 2 - Write a short explanation for each of the...Ch. 2 - Prob. 38RQCh. 2 - Prob. 39RQCh. 2 - Prob. 40RQCh. 2 - Prob. 41RQCh. 2 - Prob. 42RQCh. 2 - Prob. 43RQCh. 2 - Prob. 44RQCh. 2 - Prob. 45RQCh. 2 - Prob. 46RQCh. 2 - Prob. 47RQCh. 2 - What information is normally stored in the ROM...Ch. 2 - Prob. 49RQCh. 2 - Prob. 50RQCh. 2 - Prob. 51RQCh. 2 - Prob. 52RQCh. 2 - Prob. 53RQCh. 2 - Prob. 54RQCh. 2 - Prob. 55RQCh. 2 - Prob. 56RQCh. 2 - Prob. 57RQCh. 2 - Prob. 58RQCh. 2 - Prob. 59RQCh. 2 - Prob. 60RQCh. 2 - What is the function of a transducer?Ch. 2 - Prob. 62RQCh. 2 - Prob. 1PCh. 2 - Assume a thermocouple, which supplies the input to...Ch. 2 - With reference to I/O module specifications: a. If...Ch. 2 - Prob. 4PCh. 2 - Prob. 5PCh. 2 - Prob. 6P
Knowledge Booster
Background pattern image
Similar questions
SEE MORE QUESTIONS
Recommended textbooks for you
Text book image
Systems Architecture
Computer Science
ISBN:9781305080195
Author:Stephen D. Burd
Publisher:Cengage Learning
Text book image
A+ Guide to Hardware (Standalone Book) (MindTap C...
Computer Science
ISBN:9781305266452
Author:Jean Andrews
Publisher:Cengage Learning
Text book image
Enhanced Discovering Computers 2017 (Shelly Cashm...
Computer Science
ISBN:9781305657458
Author:Misty E. Vermaat, Susan L. Sebok, Steven M. Freund, Mark Frydenberg, Jennifer T. Campbell
Publisher:Cengage Learning
Text book image
Fundamentals of Information Systems
Computer Science
ISBN:9781305082168
Author:Ralph Stair, George Reynolds
Publisher:Cengage Learning
Text book image
Principles of Information Systems (MindTap Course...
Computer Science
ISBN:9781305971776
Author:Ralph Stair, George Reynolds
Publisher:Cengage Learning
Text book image
A+ Guide To It Technical Support
Computer Science
ISBN:9780357108291
Author:ANDREWS, Jean.
Publisher:Cengage,