Industrial Process Control(Lab)

Comparison and Mathematical instructions (Lab 2)

Zaib.zafar@nu.edu.pk FAST Isb Engr.jahanzaib Zafar

Objective’s of today Lab Familiar with different types of Memory How to Access Memory Familiar with different types of DATA types Familiar with different types of comparison

instructions Basic of timers

Types of Registers in PLC 1. Process-Image Input Register: I2. Process-Image Output Register: Q3. Variable Memory Area: V4. Accumulators: AC5. Special Memory: SM6. Timer Memory Area: T7. Counter Memory Area: C8. High-Speed Counters: HC9. Analog Inputs: A10. Analog Outputs: AQ11. Sequence Control Relay (SCR) Memory Area: S12. Bit Memory Area: M

How to access Memory Area The memory registers of Can be: Bit Accessible Byte Accessible Word Accessible Double Word Accessible

How to access Bits of Memory

Byte, Word & Double Access

Data Types & Ranges

Compare Instructions Use for comparison of the following data

types:

LAD Symbols for Byte Comparison:

Compare Integer: same way we can compare integer but:Integer comparisons are signed.

LAD Symbols for Integer Comparison:

Compare DoubleDouble word comparisons are signed

Math instructions:

The math instructions includes: instructions add or subtract two 16-bit integers and produce a 16-bit result (OUT) SM1.1 bit is an overflow flag. SM1.2 (negative)

Multiplication & Division Instructions• The Multiply Integer instruction multiplies

two 16-bit integers and produces a 16-bit product.

• The Divide Integer instruction divides two 16-bit integers and produces a 16-bit quotient. No remainder is kept.

SM1.1 (overflow) flag SM1.3 (divide-by-zero) flag. Increment & Decrement Instructions:The Increment Byte and Decrement Byte instructions add or subtract 1 to or from the input byte (IN) and place the result into the variable specified by OUT.

Introduction with timer Instruction two types of timers available with different

resolutions : T Delay ON T Delay OFF

When timer value reaches at “PT” it turn on ‘TXX ‘ Contact.

Example: (timer working)

Lab Tasks Task 1Construct the following LADs using the STEP 7-Micro/WIN 32. ladder are given in the Lab Manual. Task 2:A circuit consists of 10 LEDs. The sequence of glowing of LED is in such a way that after every five seconds a LED glows. As a LED glow, it turns off the LED which is glowing already. So at any time only one LED can glow. After completing one loop, all LEDs are switched off automatically and repeat the previous cycle again.Construct Ladder Logic Diagram to implement the given circuit.

Task3:Implementation of calculator:Design a calculator which can add , multiply , subtract, divide, also have capability to have to overflow handling capability.