PLC Revision

PLC Revision

1. Differences between open source and proprietary software.

   • Anyone can download it and use it straightaway. There would usually be a lot of online support because its widely used.
   • This software is produced without the source code. Because of the programs license agreements this software can not be copied and/or resold or distributed without permission. The owner of the software will have rights on their software.

2. bit= 1bit. nibble=4bits. byte= 8bits. kilobyte= 1,000bytes. megabyte= 1,000,000bytes. gigabyte= 1,000,000,000bytes. terabyte= 1,000,000,000,000bytes.

3. Character - A single character Real - Decimal numbers Integer - Whole numbers Boolean - True/False String - Any characters

4. Sequence - A list of instructions Selection - Decisions (IF, ELSE IF, ELSE) Iteration - Repeating code.

5. The different threats that pose to a network

   • malware, phishing, people as the ‘weak point’ in secure systems (social engineering), brute force attacks, denial of service attacks, data interception and theft, poor network policy.

6. Ways to prevent network threats

   • penetration testing, network policies, anti-malware software, firewalls, user access levels, passwords, encryption.

7. Character - A single character Real - Decimal numbers Integer - Whole numbers Boolean - True/False String - Any characters