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How to know which modbus address to define for a slave?

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I've never worked with modbus so apologies if this should be obvious.

Our vendor is creating a PLC device for our application and wants to know what address it should be on (it's the slave). Our application being the master, running on a cRIO-9045. How do I work this out? We don't have any other modbus devices, only a few RS232. 

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CLD
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Message 1 of 5
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Pick a slave address (1..247) that doesn't collide with other devices on the same network.

 

Of course if there will be future devices on the same network, this might not be that easy.

 

In this case, you might want to avoid 1 or 2, that could be defaults of other devices...

 

Most devices allow changing the address, but it is convenient to not have to change a factory setting... 

 

 

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Thank you! Okay so if I don't have any other modbus items it would be reasonable to pick address 3? 

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Solution
Accepted by topic author Shiv0921

@Shiv0921 wrote:

Thank you! Okay so if I don't have any other modbus items it would be reasonable to pick address 3? 


If you sure you'll never get other devices, you might as well pick 1.

 

If I got a modbus device and no documentation about it's address, I'd try 1 first. And then 2. And then try all addresses in a for loop. That would take 10 minutes to build and test...

 

To summarize, if there are no other devices, it basically doesn't matter at all.

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Okay thank you!

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CLD
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