Chapter 11, Problem 11P

Program Plan Intro

Count-Up (CTU) Counter:

• The CTU counter refers to an up counter
• This counter is used to count an event that occurs logically or externally and places that value in the counter’s accumulator.
• The accumulated value can even be maintained during false rung conditions and can be reset back to 0 using reset instruction.

Math functions:

The basic math functions performed by PLCs are as follows:

• Addition
  • This function is used to add one piece of data to another.
  • It is also called as ADD.
• Subtraction
  • This function is used to subtract one piece of data from another.
  • It is also called as SUB.