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Member
braxat2000
Posts: 13
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labiew lib for modbus over RS485 over USB

Hi,

I have the following problem which I would be grateful for any help to solve.

 

I have a digital meter device (lumel NA5) which has RS485 interface, and modbus protocol over it.

 

A possible solution I'm contemplating is to get a RS485 to USB converter, and then talk to the device from Labview.

I found Labview library for serial and TCP/IP modbus. But is it possible to connect to this device using UCB?

 Thanks,

Eyal. 

Active Participant
Hueter
Posts: 301
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Re: labiew lib for modbus over RS485 over USB

You can use this


1-Port RS485/422 Interface for USB



or if you need more ports...


2-Port RS485/422 Serial Interface for USB


4-Port RS485/422 Serial Interface for USB

 

With this device the serial ports will show up like any other COM port, you can target it in LabVIEW or third party software.

Active Participant
K C
Posts: 1,670
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Re: labiew lib for modbus over RS485 over USB

Hi,

 

I use USB-uarts from FTDI. Place it on a small PCB add a RS-485 transceiver. With this you have a RS-485 interface as a normal COM port.

You can also buy complete USB-RS-485 interface. No experience with those but I am sure that most of them just works fine if you need a 'standard' communication.

Member
braxat2000
Posts: 13
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Re: labiew lib for modbus over RS485 over USB

Hi,

Thank you very much, I'll check it out.

All the best,

Eyal.

Member
Sasa12345678
Posts: 8
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Rif.: labiew lib for modbus over RS485 over USB

Salve a tutti,

 

vorrei sottoporvi una questione: avendo realizzato un convertitore usb-RS485 fatto in casa, MAX può riconoscerla come porta seriale?


braxat2000 ha scritto:

Hi,

I have the following problem which I would be grateful for any help to solve.

 

I have a digital meter device (lumel NA5) which has RS485 interface, and modbus protocol over it.

 

A possible solution I'm contemplating is to get a RS485 to USB converter, and then talk to the device from Labview.

I found Labview library for serial and TCP/IP modbus. But is it possible to connect to this device using UCB?

 Thanks,

Eyal. 


 

Member
ColdenR
Posts: 167
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Rif.: labiew lib for modbus over RS485 over USB

MAX will probably not be able to recognize your USB-RS485 converter. It's possible that it would work - the best way to find out is to try.

 

But if you want to use National Instruments software you should probably just purchase one of the converters linked above (such as http://sine.ni.com/nips/cds/view/p/lang/en/nid/12845).

Colden Rouleau

Product Support Engineer | NI-RIO R&D | National Instruments
Active Participant
K C
Posts: 1,670
0 Kudos

Rif.: labiew lib for modbus over RS485 over USB

Since the earlier mentioned FTDI devices acts like a normal COM port it will be recognized by MAX.

I use them a lot. Works perfectly.

 

If you want a solution that works without adding an interface circuit follow the link of Colden R

 

If you can solder and are able to add a RS-485 interface circuit to the FTDI device follow my solution.

 

There is a price difference  :smileywink: