question

Lukas Ronge avatar image
Lukas Ronge asked

Modbus TCP - different devices, same Unit ID

Hello,


I have upgraded my system from SmartSolar 250/70-Tr VE.Can to latest SmartSolar RS 450/100-Tr (with latest firmware), but now I have a problem with Modbus TCP because SmartSolar RS now has same Unit ID as installed SmartShunt (both 238). Old MPPT has Unit ID 239 and everything Modbus TCP related was fine.

Installed Venus OS version is latest v2.65~8.

Both devices are connected via VE.Direct-USB to different USB ports.

Is any possibility to change it somehow ? Because now I can`t read Modbus registers correctly.

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MPPT SmartSolarVenus OSSmartShuntModbus TCP
1616846254112.png (36.1 KiB)
1616846277416.png (52.4 KiB)
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2 Answers
mvader (Victron Energy) avatar image
mvader (Victron Energy) answered ·

I’m quite sure its no problem they have the same unitid: the registers don’t overlap

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Lukas Ronge avatar image
Lukas Ronge answered ·

You are right, sorry... I was confused, because it is currently (probably) not possible to read PV voltage and current (address 776 and 777)... because of multiple MPPT trackers ? PV power (on 789) is OK... Are you planning to add these trackers to ModBus TCP registers ? Thanks !

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mvader (Victron Energy) avatar image mvader (Victron Energy) ♦♦ commented ·

hi, yes; thats coming.

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Related Resources

Victron Venus OS Open Source intro page

Venus OS GitHub (please do not post to this)

Additional resources still need to be added for this topic

Modbus TCP Basics

MPPT product page

VictronConnect manual

PWM or MPPT

MPPT calculator

MPPT codes