0:00
What is the most powerful PLC instruction
0:02
You might think it's timers, counters or set and reset bit instructions
0:07
But today, we're exploring indirect or pointer instructions, arguably the most powerful tool in PLC programming
0:15
Indirect addressing, also known as pointer instructions, allows you to store or retrieve memory addresses of data or instructions
0:23
This is incredibly useful when dealing with large amounts of data or performing complex calculations
0:30
Imagine you're managing machine recipes, sequence control or storing test results. Indirect addressing can handle all of these tasks efficiently
0:39
Let's see how this works in CLICK, DoMore and Productivity PLCs. In CLICK PLCs, indirect addressing is referred to as pointer addressing
0:49
It uses DS registers as the offset value and can be applied to various data register memory types like DS, DD, DF and more
0:59
For instance, DD DS3 points to the address in DD that the DS3 value contains
1:05
If DS3 has a value of 145, the address will use DD 145
1:12
As DS3 changes, the corresponding DD address changes too, allowing you to log or retrieve values dynamically
1:20
In Productivity PLCs, we use arrays for indirect addressing. A tag name can be specified as the index of the array
1:28
making it easy to manage complex data structures. For example, widget progress pointer could be a one-dimensional array
1:35
while widget progress pointer row, pointer column could be a two-dimensional array
1:40
Individual elements are addressed by their index, making data manipulation straightforward. In DoMore PLCs, indirect addressing allows an instruction's memory address
1:51
to vary during runtime, pointing to multiple locations. All data blocks in the CPU can be used as arrays
1:59
For example, using V0 as the pointer in an array with values ranging from 1 to 6
2:03
the instruction MOV VV0 to V100 dynamically changes the data location based on V0's value
2:10
Indirect addressing, or pointer instructions, are the most powerful tools in PLC programming
2:16
They offer unparalleled flexibility, allowing you to handle large datasets, perform complex calculations, and easily troubleshoot your systems
2:25
Whether you're using CLICK, DoMore, or Productivity PLCs, indirect addressing can streamline your programming process
2:33
From machine recipes to sequence control and test result storage, the applications are endless
2:39
How many more examples and applications can you think of using indirect pointers
2:44
Let us know in the comments below. Thanks for watching and see you next time
