Quiz 3 142 CA
What is one of the drawbacks to using hand-held programmers? a. They require more time b. They are more expensive c. They lack portability d. They require backup power
a. They require more time
When a PLC is first turned ON, it will run a self-diagnostic or self-check test. a. true b. false
a. true
Which of the following is not one of the four steps in a typical program scan? a. read and solve the logic of the program ( ladder logic) b. clear ROM to accommodate new program data c. determine the status of the input device (ON or OFF) d. update the output devices (turn ON or OFF)
b. clear ROM to accommodate new program data
The actual scan time, or time it takes the PLC to complete a four-step scan, decreases as the number of the program words increases. a. true b. false
b. false
Which term describes changes that are made after a program has been loaded into the processor? a. stopgap programming b. on-line programming c. delayed programming d. off-line programming
b. on-line programming
Memory that requires a battery backup to protect data in case of a power failure is known ______. a. FLASH b. volatile c. solid-state d. EEPROM
b. volatile
1K of memory is actually ____________. a. 1,000 words b. 1,010 words c. 1,024 words d. 1,042 words
c. 1,024 words
What is a processor's maximum capacity of inputs and outputs a. 1,042 b. 256 c. 40,000 d. unlimited
c. 40,000
Which of the following can be used to erase memory in an EPROM chip? a. loss of power b. activation of an erase signal c. exposure to UV light d. removal from board
c. exposure to UV light
Reverse video of contacts and coils in a programmable device indicates which of the following? a. power failure b. memory loss c. logic continuity d. program timeout
c. logic continuity
Memory that can retain stored data following loss of power in a device is called ______________ memory. a. volatile b. solid-state c. nonvolatile d. CMOS-RAM
c. nonvolatile
A(n) __________ timer is preset to an amount of time that is slightly longer than the normal scan time. a. logic b. quartz c. watchdog d. interval
c. watchdog
Which of the following is not a type of nonvolatile memory? a. EEPROM b. PROM c. FLASH d. HMOS
d. HMOS
What is the most common type of volatile memory? a. PROM b. EAROM c. EEPROM d. RAM
d. RAM
For safety, lithium batteries should not ne exposed to which of the following? a. cold b. copper c. magnets d. watter
d. watter