PLC – Indirect Indexing

Some of the Delta PLC programmers, sometimes wonders what are those E and F index that appears on the WPLSoft wizards.
What can I use them?
So let me told you that secondary letters can save you a lot of time!!!

E and F index are the tool to do indirect calls to variables, n the typical use is to create matrix of elements. It works like the typical pointer, where you can move it along the memory mapping.

Let´s take the below program as example:

Data register (D2000)  should be the analog data of an analog input for example, and this value should change on time basis.
Memory_reg register (D7000) is the starting register where I want to save the data loggin.

Then I use E register to change the destination register of  the adquired data in the following way
MOV D2000 D7000+E0

Second 0 -> MOV D2000 D7000
Second 1 -> MOV D2000 D70001
Second 2 -> MOV D2000 D70002
etc…

For better understanding, don’t hesitate to download the program and simulate  it.

E and F registers