Activities Manual For Programmable Logic Controllers
5th Edition
ISBN: 9781259682476
Author: Frank Petruzella
Publisher: Mcgraw-hill Higher Education (us)
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Question
Chapter 11, Problem 4P
Program Plan Intro
Math instruction:
- Math instructions refer to all output instructions that uses the data of two words or registers and perform the desired function.
- Math instructions are programmed based on the type of processor used.
- The data manipulation instructions are almost similar to math instructions.
- Math instructions are normally used to perform arithmetic functions on the values stored in memory words or registers.
Math functions:
The basic math functions performed by PLCs are as follows:
- Addition
- This function is used to add one piece of data to another.
- It is also called as ADD.
- Subtraction
- This function is used to subtract one piece of data from another.
- It is also called as SUB.
- Multiplication
- This function is used to multiply one piece of data by another.
- It is also called as MUL.
- Division
- This function is used to divide one piece of data from another.
- It is also called as DIV.
Terms used:
The following terms are used in the instruction.
- Source A
- Source A refers to the address of the first piece of data that is used in the instruction.
- Source B:
- Source B refers to the address of the second piece of data that is used in the instruction.
- Destination
- Destination refers to the address where the results of the instruction are stored.
Explanation of Solution
b.
Value stored in “N7:0”:
- Consider the given word “N7:0”.
- In the given program, the word “N7:0” addresses the destination of the “MUL” instruction.
- Here, “Source A” and “Source B” of “MUL...
Explanation of Solution
c.
Value stored in “N7:1”:
- Consider the given word “N7:1”.
- In the given program, the word “N7:1” addresses the destination of the “DIV” instruction.
- Here, “Source A” and “Source B” of “DIV...
Explanation of Solution
d.
Value stored in “O:013”:
- Consider the given word “O:013”.
- In the given program, the word “O:013” addresses the destination of the “ADD” instruction.
- Here, “Source A” and “Source B” of “AD...
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Students have asked these similar questions
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The next problem concerns the following C code:
/copy input string x to buf */
void foo (char *x) {
char buf [8];
strcpy((char *) buf, x);
}
void callfoo() {
}
foo("ZYXWVUTSRQPONMLKJIHGFEDCBA");
Here is the corresponding machine code on a Linux/x86 machine:
0000000000400530 :
400530:
48 83 ec 18
sub
$0x18,%rsp
400534:
48 89 fe
mov
%rdi, %rsi
400537:
48 89 e7
mov
%rsp,%rdi
40053a:
e8 d1 fe ff ff
40053f:
48 83 c4 18
add
callq 400410
$0x18,%rsp
400543:
c3
retq
0000000000400544 :
400544:
48 83 ec 08
sub
$0x8,%rsp
400548:
bf 00 06 40 00
mov
$0x400600,%edi
40054d:
e8 de ff ff ff
callq 400530
400552:
48 83 c4 08
add
$0x8,%rsp
400556:
c3
This problem tests your understanding of the program stack. Here are some notes to
help you work the problem:
• strcpy(char *dst, char *src) copies the string at address src (including
the terminating '\0' character) to address dst. It does not check the size of
the destination buffer.
You will need to know the hex values of the following characters:
Chapter 11 Solutions
Activities Manual For Programmable Logic Controllers
Ch. 11 - Explain the function of math instructions as...Ch. 11 - Prob. 2RQCh. 11 - What standard format is used for PLC math...Ch. 11 - Prob. 4RQCh. 11 - Prob. 5RQCh. 11 - Prob. 6RQCh. 11 - Prob. 7RQCh. 11 - Prob. 8RQCh. 11 - Prob. 9RQCh. 11 - Prob. 10RQ
Ch. 11 - With reference to the instruction of Figure 11-34,...Ch. 11 - With reference to the instruction of Figure 11-35,...Ch. 11 - Prob. 1PCh. 11 - Prob. 4PCh. 11 - Prob. 5PCh. 11 - Prob. 7PCh. 11 - Prob. 8PCh. 11 - With reference to math instruction program shown...Ch. 11 - With reference to the math instruction program...Ch. 11 - Prob. 11PCh. 11 - Prob. 12P
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