Deck 40: Analog Sensing for Plcs

Question 1

Most analog sensors can produce only very weak signals.

Answer 1

True

Question 2

Signal wire should run in the same conduit with power wiring.

Answer 2

False

Question 3

It is desirable for the sensor to produce a certain amount of ____________________ instead of a certain amount of voltage because it eliminates the problem of voltage drop on lines.

Answer 3

current

Question 4

A twisted pair of signal wires surrounded by a braided shield cannot be used as a type of signal cable.

Question 5

When it is necessary to cross power wiring, install the signal cable so that it crosses at a right angle.

Question 6

In an industrial environment where intense magnetic fields and large voltage spikes abound, it is easy to lose the ____________________ in the electrical noise.

Question 7

Why should a common coaxial cable be avoided?

Question 8

It is common to find different pieces of equipment have ground levels that are several volts apart.

Question 9

One of the most common types of shielded cable uses twisted wires with a(n) ____________________ foil shield.

Question 10

What does the differential amplifier detect?

Question 11

What happens if the pressure sensor is located some distance away from the programmable controller?

Question 12

Why should wire run as short as possible?

Question 13

An electronic device that is often used to help overcome the problem of induced noise is the ____________________.

Question 14

What is the brute-force method?

Question 15

Because the sense resistor in the input of the programmable controller is the only resistance in the circuit, all of the ____________________ of the pressure sensor will appear across it.