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ModBus - SE CVM
#1
Hi,

I wish I had bit more experience with ModBus, but sadly I don't, hence the question here.

See attached screenshot. I'm making a profile for this equipment and I only need 4 registers. L1 current, L2 current, L3 current and active power for all phases. I'm after the data in the Instant column. Now, it seems the data is supplied through 2 adresses...? 02-03 points to L1 current (HEX I presume), so how do I combine these two to give me the right result?

   
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#2
Use RTU read test. Set address to 0, data type to uint32 and try different read swap values until you get a valid reading.
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#3
(23.10.2019, 10:12)admin Wrote: Use RTU read test. Set address to 0, data type to uint32 and try different read swap values until you get a valid reading.

That worked and I should have been able to figure that out myself.

Just one question; when polling register 02 (Decimal: 2) I got a correct and expected result. However, when polling register 03 (Decimal: 3) I got "Illegal *something". Why have they put two different registers in that table? Thanks for your help.

For future reference, if anyone has a Scandinavian Electric CVM Mini MC they need to get the amp results from, the decimals are:

L1 current, 2
L2 current, 12
L3 current, 22

Active power, 24

I have added a multiplier; 0,001 to the json profile.
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#4
While using uint32 you are reading 2 registers 02 and 03. Single register in modbus is 16bit.
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#5
(23.10.2019, 11:03)Daniel. Wrote: While using uint32 you are reading 2 registers 02 and 03.  Single register in modbus is 16bit.

Ah, everything makes sense now. Thank you!
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