Why did some address on modbus affect another address on node red GUI

General
1

Hi this is my project using digital modbus using rs485 connection to fanless pc.

This is the dasboard gui.DI1,DI2,DI3,DI4 all to respective address as in the manual of modbus configuration of rs485 connection.

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image.jpg4032×3024 3.65 MB

As you guys can see,my first address when i let the current flow from external wire it will affect my third address.

This is my modbus and cpu configurations using rs485 connection

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image.jpg3024×4032 2.44 MB

Why did the voltage affect with each other in the address of modbus rtu?

2

Either both modbus addresses are returning the value or you are not fetching the right addresses or you are not displaying it correctly. First use debug nodes to see what data you are actually reading. That will help identify where the error is.

3

Thank you, ill check up on that using debug tab.

Also why is my address DI1 and DI3 ,they have blink of active and inactive in every seconds but
Address DI2 and DI4 it does not blink,it stays put (active sign only)

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image.jpg2138×2851 2.22 MB

Any recommendations?

4

Impossible to say since you have not told us what node type they are or what configuration they have.

5

Those nodes on the left, are they individual connections? I.e. do you set the IPAddress etc in each one of them? if so then cant you change it to one node and request 4 items from D11?

Also, what data type are you using? If LONG or a 32 bit item, values may overflow the registers (I believe modbus is 16bit by design)

As you haven't stated the node type (node-red-contrib-modbus????) and haven't posted your flow, i suspect you aren't gonna get a lot of help.