Structured Text PLC Programming Example for Input & Output Tag Aliasing Assignments

Structured Text PLC Programming Example for Input & Output Tag Aliasing Assignments
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One of the ways we utilize Structured Text to speed up machine development is through input and output assignment. In a typical system integration environment, one would have to create a rung dedicated for every input and output in order to pass the data to an internal tag of the PLC. The reason for this practice was discussed in a tutorial on tag aliasing we've released before. In short, by doing so, we can easily reassign and expand our tags as the program changes.
As you design a new piece of equipment or system, it's important to keep documentation of every point of input and output. More often than not, this documentation would be kept in an Excel spreadsheet and used by electricians during the installation phase and by engineers during the commissioning phase. In other words, it's a list of all the inputs and outputs of the system identifying their location and what they're connected to in the field.
By using Structured Text over ladder logic in this specific case, programmers can create simple string manipulations in Excel and implement the entire tag architecture through copy pasting entire routines. Furthermore, by taking this approach, it becomes much easier to make changes to an existing system and to export the information of data into other structures or databases.
Full Tutorial:
www.solisplc.com/tutorials/structured-text-example-for-input-output-tag-aliasing-assignments
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[@PLCProgrammingCourses]

Nice video 😊

[@robokane1187]

Nice explanation but you make it sound like mapping in ST puts in the Description automatically when you import it from your spreadsheet. In fact at ~9:30 in the video you even comment about having to create the Description by hand if all those same tags were created in Ladder Logic. But, looking closely at your video, when you went into Controller Tags the Description column was still blank. So, while I do see some time saving advantages, it is still required by the Programmer to Right Click and Create any new tags, confirm the Scope and add a Description.

[@plcplc3138]

hye.
nice vid.can I say this is the same method as we would do for analog?
The following formula is used to convert analog values:
Scaled value = (Input value * Rate) + offset
Where:
Rate = (Scaled max) / (Input max - Input min)
Offset = Scaled min - (Input min * Rate)
Meaning of individual variables:
Scaled value - in physical units
Input value - The current value at the analog card input
Rate - The conversion constant
Scaled max - Maximum value (in physical units eg 100bar)
Scaled min - Minimum value (in physical units eg 0bar)
Input max - Maximum unit on the analog card input (32767)
Input min - Minimum unit on analog card input (0)
Offset - Correction of recalculated value