Page 249 - Programmable Logic Controllers, Fifth Edition - Mobile version

CHAPTER 10 REVIEW QUESTIONS

1. In general, what do data manipulation instructions 10. What is the advantage of using the file copy (COP)
allow the PLC to do? or fill file (FLL) instruction rather than the FAL in-
2. Explain the difference between a register or word struction for the transfer of data?
and a table or file. 11. What are data compare instructions used for?
3. Into what two broad categories can data manipula- 12. Name and draw the symbols for the six different
tion instructions be placed? types of data compare instructions.
4. What takes place with regard to a data transfer 13. Explain what each of the logic rungs in
instruction? Figure 10-48 is instructing the processor to do.
5. The MOV instruction is to be used to copy the 14. What does the limit test (LIM) instruction test
information stored in word N7:20 to N7:35. values for?
What address is entered into the source and the 15. How are multibit I/O interfaces different from the
destination? discrete type?
6. What is the purpose of the mask word in the MVM 16. Assume that a thumbwheel switch is set for the
instruction? decimal number 3286.
7. List three types of data shifts used with file a. What is the equivalent BCD value for this
instructions. setting?
8. List the six parameters and addresses that must b. What is the equivalent binary value for this
be entered into the file arithmetic and logic (FAL) setting?
instruction. 17. Assume that a thermocouple is connected to an
9. Assume the ALL mode has been entered as part of analog input module. Explain how the tempera-
a FAL instruction. How will this affect the transfer ture of the thermocouple is communicated to the
of data? processor.

Ladder logic program
Input Output
L1 A EQU B L2
EQUAL
A Source A N7:400
B
Source B N7:401

(a)
Input Output
L1 C LES D L2
LESS THAN
C Source A N7:500
D
Source B 250

(b)
Output
L1 E GEQ F L2
GREATER THAN OR EQUAL
E Source A N7:601
F
Source B N7:600
30
(c)
Figure 10-48 Logic rungs for Question 13.

230 Chapter 10 Data Manipulation Instructions

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