Basic PLC Ladder Programming Examples 20

Basic PLC Ladder Programming Examples 20

 

Basic PLC Ladder Programming Training Examples for Beginners.

 Hi friends, here we are starting unique a series of Free Training on PLC Ladder Programming & tutorials. These PLC Ladder Programs are important to learn basics of Ladder programs.

 PLC Ladder Practice Problem: 
Summation of Continuous D Registers
·
Summing up the values of D registers from D101 to DN (the number of N is determined by users) and storing the operation result in D100. If the result < K-32768, the borrow flag = ON; if the result > K32767, the carry flag = ON

Topics Covered in this example is FOR NEXT PLC instructions of Ladder Program.
Number of PLC Outputs Required
Y0 Borrow flag indicator. When the value in D100 < K-32768, Y0 = ON Y1 Carry flag indicator.
When the value in D100 > K32767, Y1 = ON
Number of PLC Data Registers Required
D100 Storing the sum of all D registers
D500 Storing the executing times of FOR-NEXT loop
PLC Ladder Programming:
Basic PLC Ladder Programming Examples 20
Basic PLC Ladder Programming Examples 20

 

PLC Ladder Program Description:
·      The key of the program is to use the index register E1 together with FOR ~ NEXT loop to vary
the addend D100E1. When E1 = K1, D100E1 represents D101; when E1 = K2, D100E1
represents D102. Also, when E1 = K10, D100E1 represents D110.
·      The number of continuous D registers is determined by the execution times of FOR ~NEXT loop which is set by D500. If the value in D500 ≤ 1, the loop will execute 1 time.
If the value in D500 = K10, the loop will execute 10 times first and then
execute the instructions behind 4. Index Registers E, F Design Examples 4-2
DVP-PLC Application Examples the loop.
·     In the first FOR ~ NEXT loop, E1 = K1, so D100E1 represents D101. ADD instruction is executed, and the operation result of D100 plus D101 is stored in D100. Since the summand
D100 = K0, the value stored in D100 equals to the value in D101. At the same time, INC instruction is executed to set E1 = K2.
·      In the second FOR ~ NEXT loop, E1 = K2, so D100E1 represents D102. ADD instruction is
executed, and the operation result of the values of D100 plus D102 is stored in
D100. Since the summand D100 = D101, the value stored in D100 is the sum of the
D101 and D102.
·      According to the same process, by the 10th FOR ~ NEXT loop the value in D100 will be the sum of D101, D102, D103, D104, D105, D106, D107, D108, D109 and D110.
·      If the operation result < K-32768, M1021 will be ON to activate the output coil Y0. Borrow
flag indicator will be ON. On the contrary, if the operation result > K32767, M1022 will be ON to activate output coil Y1. Carry flag indicator will be ON in this case.

 
Note: Example is only for training purposes. No practical implementation is done. See More PLC Ladder Programming Examples

PLC Ladder Programming Example 1

http://www.plc-scada-dcs.blogspot.com

Leave a Comment

Ads Blocker Image Powered by Code Help Pro

Ads Blocker Detected!!!

We have detected that you are using extensions to block ads. Please support us by disabling these ads blocker.

Powered By
CHP Adblock Detector Plugin | Codehelppro