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inverter voltage and ampere data taking with usb rs485


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hello, 

i am working with solar inverter and i want to acquire voltage and ampere with USB RS485 as modbus.

i am using LABVIEW 2012 and visa serial in LABVIEW.

i already make it but the chart doesnt show anything.

could you please help or make a little correction in my block diagram.

here is my block diagram *first to acquire voltage

 

thankyou for your kind attention and help :)

Untitled 1.vi

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  • 2 weeks later...

Shaun has given you the link.

 

What seems that is unclear to you, is what is involved. Modbus is a communication protocol. A way do do things like for example reading or writing numeric values to "registers", by sending formatted messages to the instrument across the serial line, across ethernet, or anything else. As such, you have probably to go to the manual of your instrument, and look up which register corresponds to reading V, I, or what else you need. You can't just expect to write the character "1" to the serial port and expect that the instrument responds in no time with a string, as you're doing in your VI. The modbus library referenced above has VIs for accessing registers, the rest of the information (which register, which port, when, what) you have to provide yourself.

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Shaun has given you the link.

 

What seems that is unclear to you, is what is involved. Modbus is a communication protocol. A way do do things like for example reading or writing numeric values to "registers", by sending formatted messages to the instrument across the serial line, across ethernet, or anything else. As such, you have probably to go to the manual of your instrument, and look up which register corresponds to reading V, I, or what else you need. You can't just expect to write the character "1" to the serial port and expect that the instrument responds in no time with a string, as you're doing in your VI. The modbus library referenced above has VIs for accessing registers, the rest of the information (which register, which port, when, what) you have to provide yourself.

yes i am very new using this labview. i usually use matlab or qt for programming. i know that labview is more practical but this is the very first time i use it. i dont even have a clue for the modbus library and how to use it =(

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If your instrument talks modbus (you say), then you have to talk modbus to it. This has little to do with the programming language.

 

I attach a snippet of mine which I've used in the past to check basic communication using the library referred above, hope it helps.

 

ModbusTester.vi

Edited by ensegre
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If your instrument talks modbus (you say), then you have to talk modbus to it. This has little to do with the programming language.

 

I attach a snippet of mine which I've used in the past to check basic communication using the library referred above, hope it helps.

 

attachicon.gifModbusTester.vi

i am sorry that just now i am replying you, i actually did it! thank to you and now i have more problem in getting the real time data.

you can see my vi there.

btw, thankyou so much for your kind help!

here is my final vi 

#but sadly i cant get the real time data :(

vi.vi

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