- monitoring and control systems

Question 1

monitoring systems

Answer 1

• Physical properties can be measured by sensors e.g., temp, pressure, motion
• Used to create a record of the condition of the system over time
• Detects when physical properties of a system go outside the desired range
  E.g., temp – traditional (human and thermostat) automatic (sensors, microprocessors and thermocouple (output V that changes with temp))
• No built-in intelligence – takes no action if value is too high/low

Question 2

control systems

Answer 2

-Take action (control) as well as monitoring
-Controls using actuators and sensors
-Actuator – cause actions based on the signal of a value sent to it

Question 3

Closed loop feedback control system

Answer 3

• Desired value for output >Controller> actuator> process (or > actual output) > sensor> controller

Question 4

Bitwise manipulation

Answer 4

-Used within AL to monitor or control devices
E.g., Can reset flags from 1 to 0 by applying the AND #B00000000 operation - 1 AND 0 > 0 so resets from 1 back to 0
Eg XOR #B00000001 - toggles the value using the 1 –if it’s a 1 XOR 1 becomes 0 or a 0 XOR 1 becomes a 1
Eg OR #B00000001 makes the value become 1