Deck 20: Structured Text Programming

Question 1

____________________ can be PLCs, personal computers, HMIs, intelligent I/O devices, routers, and bridges, to name just a few examples.

Answer 1

Nodes

Question 2

Explain why early PLC networks were considered proprietary.

Answer 2

These were considered proprietary networks since they were only compatible with their own equipment.

Question 3

A ring network is a network topology in which nodes are connected in parallel to form a ring.

Answer 3

False

Question 4

The ____________________ is the typically high-speed, low-error data network covering a relatively small geographic area (up to several thousand meters).

Question 5

As industrial plants began to implement PLCs in a distributive or modular approach to controlling equipment, it was necessary to develop fast, ____________________, and reliable communications schemes to tie the various PLCs and their systems together.

Question 6

Explain why the star topology is becoming more common for control networks.

Question 7

When devices are connected to network media, they are called nodules.

Question 8

One of the first methods used to communicate between PLCs was a pair of wires connecting the output card of one PLC to the input card of a second PLC.

Question 9

Explain why coaxial cable is still in wide use in industrial control systems.

Question 10

Explain the term packet.

Question 11

Explain what makes a MAN different from a WAN.

Question 12

When twisted-pair cables are used in industrial control networks, the manufacturers of the equipment will typically specify the type and quality of the cable to be used for optimum performance.

Question 13

Metropolitan Area Networks (MANs) are data communications networks that generally span a metropolitan area.

Question 14

Category ____________________ cable is a shielded multi-pair high performance cable with transmission rates up to 700 MHz.

Question 15

A(n) ____________________ network is a topology in which nodes are connected to a common backbone in a daisy chain or multidrop fashion.