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Fix “V-Memory not allocated for library…” STEP7 MicroWIN V4.0

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Hello friends!
For PLC Siemens S7-200, in order to use Modbus-RTU communication protocol, we must use VB (Variable Memory) memory area for Modbus instructions, if not declared when compiling the program will appear the following error:

ERROR 18: V-Memory not allocated for library. Select right mouse menu item “Library Memory…” from the Block Diagram in the instruction tree.

To fix this error is very simple, we just need to add the VB memory area to the Siemens S7-200 Memory Area Library on MicroWIN 4.0 software

Video Tutorial


>>> Download Siemens S7-200 Modbus Library Free

If you need any assistance in adding Mobbus library as well as programming peripherals through this protocol, please comment below the article, will answer you as soon as possible.

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