Hi! Im creating a Dashboard to show diferent values extracted from an equipment. I can read the just 5 modbus adress, but when I try to get 6 or more readings lost all the connections. How can I fix it?
Hi unfortunately nowhere near enough info I'm afraid.
What device is it? What address are you accessing? Can you link to a manual that lists the registers?
Lastly, can you clarify this ...
... What exactly happens?
Hi! Im Agree, I going to try to be clearest:
Device: Battery Energy Storage System-
Address: I can read any address, but just 5 as maximum, If I try to read 6 address so it disconnect some nodes.
In the first image Just reading 5 address (from 12295 to 12299) and all ok:
In the second image trying to read 6 address (from 12295 to 12300) but I dont understand why it disconnect some nodes:
Function Code: 3 read holding register
Poll rate: 2 seconds
best regards!!
I read 60 registers with no issue but use only one node. why do you have so many nodes ?
can you not put address 12295 and put 10 quantity ?
can you show the setting of the node like above ?
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This is the least efficient and most problematic way of gathering data I'm afraid. This document has some good advice and practical info directly related to your requirement: Modernize your legacy industrial data. Part 2. • FlowFuse
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Thanks, I Feel this is the best option. But Im concerning about use just one node in my scenarios , let me show you how the registers address are distributed:
In this case, is ok read in one node from 257 until 24643 address? it mean 24386 registers, I feel it is a lot, but Im not sure if it is any problem.
Thanks! I read it, it is too helpful to understand more about the modbus efficiency!
No, the maximum read count is 125 registers in one request.
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Got it. So, it is a limitation for my case? is any way to get all the data? or should I look for something different to node-red?
The limitation is the modbus specification, not node-red. Other software will have exactly the same limitations. The are some exceptions like certain PLC's but typically, 125 is the protocol limitation
Your best bet is to read those ranges 1 at a time by connecting the modbus nodes in series instead of parallel.
Thanks, do you mean something similar like this?? How to create an Modbus-TCP alarm status dashboard - #20 by Steve-Mcl
In series, like that example, yes.
thanks it work for me. Is my first time in this forum and the experience was so good.
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