Deck 40: Analog Sensing for Programmable Logic Controllers

Question 1

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

Answer 1

input signal

Question 2

Why should wire run as short as possible?

Answer 2

A long wire has more surface area to pick up stray electrical noise.

Question 3

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

Answer 3

True

Question 4

Why should a common coaxial cable be avoided?

Question 5

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

Question 6

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

Question 7

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.

Question 8

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

Question 9

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

Question 10

Most analog sensors can produce only very weak signals.

Question 11

What does the differential amplifier detect?

Question 12

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

Question 13

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

Question 14

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.

Question 15

What is the brute-force method?