PLC Programmable Logic Control Relay Logic Circuit Basic

PLC Programmable Logic Control Relay Logic Circuit : Basic Concept By Mohd Haffiz Zainal Abidin College Community Electrical Lecturer

CONTROL CIRCUIT 24 VDC L 1 RED STOP PB 0 VDC START PB K 1 A 1 CR K 1 -NO BUZZER *CR=Control Relay A 1=+ve 24 VDC Supply A 2= -ve 0 VDC Supply K 1 = Reference for Relay CR A 2 L 2 BLK

CONTROL CIRCUIT 24 VDC L 1 RED STOP PB 0 VDC START PB K 1 A 1 CR K 1 -NO BUZZER *Start Button press A 2 L 2 BLK

CONTROL CIRCUIT 24 VDC L 1 RED STOP PB 0 VDC START PB K 1 A 1 CR K 1 -NO BUZZER *Start Button press A 2 L 2 BLK

CONTROL CIRCUIT 24 VDC L 1 RED STOP PB 0 VDC START PB K 1 A 1 CR K 1 -NO BUZZER *Start Button press-> power supply continue on ladder-> CR will energize. A 2 L 2 BLK

CONTROL CIRCUIT 24 VDC L 1 RED STOP PB 0 VDC START PB K 1 A 1 CR K 1 -NO BUZZER *Start Button press-> power supply continue on ladder-> CR will energize. ->NO become NC A 2 L 2 BLK

CONTROL CIRCUIT 24 VDC L 1 RED STOP PB 0 VDC START PB K 1 A 1 CR K 1 -NO BUZZER *Start Button press-> power supply continue on ladder-> CR will energize. ->NO become NC -> K 1 -NO connect power supply in ladder. A 2 L 2 BLK

CONTROL CIRCUIT 24 VDC L 1 RED STOP PB 0 VDC START PB K 1 A 1 CR K 1 -NO BUZZER *Start Button press-> power supply continue on ladder-> CR will energize. ->NO become NC -> K 1 -NO connect power supply in ladder. A 2 L 2 BLK

CONTROL CIRCUIT 24 VDC L 1 RED STOP PB 0 VDC START PB K 1 A 1 CR K 1 -NO BUZZER *Start Button press-> power supply continue on ladder-> CR will energize. ->NO become NC -> K 1 -NO connect power supply in ladder ->Start Button depress A 2 L 2 BLK

CONTROL CIRCUIT 24 VDC L 1 RED STOP PB 0 VDC START PB K 1 A 1 CR K 1 -NO BUZZER *Start Button press-> power supply continue on ladder-> CR will energize. ->NO become NC -> K 1 -NO connect power supply in ladder ->Start Button depress ->Holding Circuit Function A 2 L 2 BLK

CONTROL CIRCUIT 24 VDC L 1 RED STOP PB 0 VDC START PB K 1 A 1 CR K 1 -NO HOLDING CIRCUIT K 1 -NO BUZZER *Start Button press-> power supply continue on ladder-> CR will energize. ->NO become NC -> K 1 -NO connect power supply in ladder ->Start Button depress ->Holding Circuit Function A 2 L 2 BLK

CONTROL CIRCUIT 24 VDC L 1 RED STOP PB 0 VDC START PB K 1 A 1 CR K 1 -NO HOLDING CIRCUIT K 1 -NO BUZZER *Stop Button press A 2 L 2 BLK

CONTROL CIRCUIT 24 VDC L 1 RED STOP PB 0 VDC START PB K 1 A 1 CR K 1 -NO BUZZER *Stop Button press-> power supply discontinue on ladder-> CR will de-energized A 2 L 2 BLK

CONTROL CIRCUIT 24 VDC L 1 RED STOP PB 0 VDC START PB K 1 A 1 CR K 1 -NO BUZZER *Stop Button press-> power supply discontinue on ladder-> CR will de-energized. ->NC become NO -> K 1 -NO disconnect power supply in ladder. A 2 L 2 BLK

• Every PLC have its own I/O Addressing format i. e the address of Inputs and Outputs in PLC. In this article discuss the I/O Addressing scheme in Omron PLC and the Timer , counter instructions format in OMRON PLC. We will see the addressing of analog Input and Output also and the DATA words and Memory bit addressing scheme. I/O Addressing Format in Omron PLC | Input and Output Addressing : Before going in to the addressing , first of all let us understand the numbers of input and output distribution. The ratio of Input to Output in Omron PLC is always 3/2 i. e if we have a PLC of 40 I/O then there will be 24 inputs and 16 outputs. Note : - Only in Compact PLC. Input Addressing Format : - In Omron PLC there are 12 inputs in one slot so addressing start from 0. 0 to 0. 11 and then 1. 0 to 1. 11 and so on. So if there are 18 inputs then address of input will be from 0. 0 to 0. 11 and 1. 0 to 1. 7. Output Addressing Format : - In Omron PLC there are 8 outputs in one slot and the addressing is as follows : CPM 1 A/CPM 1 A PLC : - 10. 0 to 10. 7 , 11. 0 to 11. 7 and so on. CP 1 E/CP 1 H PLC : - 100. 0 to 100. 7 , 101. 0 to 101. 7 and so on. Other Memory Areas : Work Bits : - As we all know that every PLC have some internal bits to be used in program these are known as memory or work bits. In Omron PLC these are called WORK bits and denoted by W. Addressing Format : - w 0. 0 to w 512. 0 Note : - There are 16 bits in one words , so w 0. 0 to w 0. 15 and then w 1. 0 to w 1. 15 Also here one important point to see is that these are used as Bits but if you want to use them as WORDS that is also possible. DATA MEMORY WORDS : - The data memory words in PLC are used to store the integer value or float value. In OMRON PLC these are denoted by D and addressing Format is D 0 to D 322767. HOLDING REGISTER : - In OMRON PLC the Holding registers are there , it is similar to Data Words except it retains its state even after power failure and also we can use it as Bits or Word. Addressing Format : - H 0 to H 1535 ( is using as words) Addressing Format : - H 0. 0 to H 1535. 15 CIO : - CIO i. e Common Input Output , these can be used as Bits or words , it is the same as we discussed before Input and Output Addressing Format : - CIO 0. 0 to CIO 6143 Note : - The amount of DM , W , H and CIO in a PLC depends upon the PLC memory and vary from PLC to PLC , you can check it in the Memory table of PLC. Timer / Counter Instructions in Omron PLC : Timers are extensively used in PLC while developing the program for any application. In Omron there are different types of timer classified according to their Timer Base value like 100 ms , 10 ms. Addressing Format of Timer : - TIM X #Y where : - X is the Timer Number and it is from 1 to 4095. and Y is the preset value of the Timer. Note : - In Omron PLC all the Timer are count-down , so when the timer starts the value start decrementing from the preset value and when it reaches 0 the timer is HIGH. Addressing Format of Timer : - CNT X #Y where : - X is the Counter Number and it is from 1 to 4095. and Y is the preset value of the Counter. Very Important Note : - The Timer and Counter value can not be same in Omron PLC. For example if you have used TIM 1 then you cant use CNT 1. How to Put Input / Output and Instructions in CX-Programmer : -