I want to sent the alarm from PLC system to an Arduino. I decide to use Modbus protocol (RS-232) because my existing PLC can communication by this protocol without additional module. I use PLC as Master and Arduino as slave. I doesn't have any background of Modbus protocol so please advice me some library that easy to use for beginner.
My aim is to sent the alarm data from PLC system in group 16 bits and write to arduino-uno after that arduino will read that data and perform some function depend on characteristic of that alarm. The protocol of communication is Modbus on RS232. I have already attached the example of Modbus mapping list and example of data structure in this topic. My questions are:
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Please advice me some of modbus library that base on RS232.
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Data from PLC are send to arduino in group of 16 bits. Each bit mean each alarm from PLC system. So how can I create a table of alarm list in arduino. So after some bit change they will compare with this table to interpret which alarm in PLC system occur.
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If I already connect to PLC by RS232 and want to see the status by serial monitor in arduino program, How can I do that?
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Please suggest me what program that can turn PC to Modbus master which can communicate with Arduino for simulation before interface real PLC.
Thank you for any comment.
