NI LabVIEW Modbus API Discussion

[suvi1990]

Hi

I am using the modbus library 1.1.5.39, to communicate with a sensor using Modbus RTU over serial line. The problem is my VI works fine and the EXE works fine too, when run on a pc with LabVIEW installed on it (LV 2013). When I run the exe on a PC with no LabVIEW (lets call it pilot PC) installed, I get an error 56. I tried it as an installer also and included the NI runtime and NI Visa runtime, but still did not work.
Do we need any additional runtime libraries to use it as an EXE.

Thanks in anticipation

Regards

Suvansh

[smithd]

No special runtime needed. Since this is a different computer are you sure the visa resource is the same as what's stored on the exe?

[suvi1990]

Yep, it was a visa resource problem. All sorted now, works fine

Thanks.

[Desruelle_luc]

Hi Smithd, Hi everybody 

I've used this API successfully to create a RTU Master, IP Master or IP Master with a gateway, RTU over TCP... and my new goal is to add new Modbus functions.

I have to add functions that are not in the Modbus Master API master, for example 18, 21, 22... I know how to write the code for the function. But the problem is that the Master class is protected. So I can’t add to the API

How to do ?

Many thanks

Luc

[smithd]

You would want to create a child class of the "master api" class. This (inc an example) is described here:

https://decibel.ni.com/content/message/58374#58374

If have trouble the template I can send another example I made for someone communicating with a specific device.

[ADLB-AC]

Hi,

I'm using this to control a modbus RTU device, it's been working fine for a while but has started giving error:

-1073807298

Property Node (arg 1) in SubVIs.lvlib:RTU Data Unit.lvclass:Read ADU Packet.vi:50300001 -> Modbus Master.lvclass:Write Single Holding Register.vi:24700001 -> Modbus Module.vi -> RT Top Level.vi

Any ideas on possible causes?

[paulmhl]

Hi what I am doing is to make The MOBUS API working with ARM processor cortex M3,is it possible?

[smithd]

paulmhl wrote:

Hi what I am doing is to make The MOBUS API working with ARM processor cortex M3,is it possible?

I'm not sure what you mean here. Do you want to communicate with an arm processor? Do you want to run labview and this library on the m3?

[smithd]

ADLB-AC wrote:

Hi,

I'm using this to control a modbus RTU device, it's been working fine for a while but has started giving error:

-1073807298

Property Node (arg 1) in SubVIs.lvlib:RTU Data Unit.lvclass:Read ADU Packet.vi:50300001 -> Modbus Master.lvclass:Write Single Holding Register.vi:24700001 -> Modbus Module.vi -> RT Top Level.vi

Any ideas on possible causes?

There are some KBs on this error on our website but they don't make a ton of sense. This might be the situation if you have a usb to serial converter: http://forums.ni.com/t5/Instrument-Control-GPIB-Serial/Error-1073807298-on-VISA-write/td-p/193177

The only two property nodes I have in there are reading baud rate and reading bytes at port, neither of which should cause an issue related to the buffer.

When does this error start happening? Does it happen ever time now, or will it work for a few minutes and then fail?

[paulmhl]

Thanks for the reply,what I am meaning is I want to run labview and MODBUS API on the M3.is it possible?