Serial Modbus with Labview 8

[philipp.n]

Hi there,

i am actually trying to develop a labview vi that should read out data from an abb protronic device via modbus serial connection. my probem is that i do not really know wher to start. when i work with modscan or quickmod it is possible to acquire some data but i have not yet gained any connection with labview. it seems that it doesn´t do anything.

would be great if someone has some hints for me

[K C]

Hi,

Can you look at this: http://forums.ni.com/ni/board/message?board.id=170&message.id=184598&jump=true

Maybe this helps.

[philipp.n]

at the moment i am a bit stuck with the work.the communication between labview and modscan works while using the ethernet but not with the serial and the modsim program does not work in any way with labview.and where can i find the labview libraries with 10001 or 30001??

[K C]

Hi,

modscan 

modsim 

libraries with 10001 or 30001 

Can you tell us what this is ? Can you also post a (basic) VI with the serial ModBus comm.

[philipp.n]

ok i try to explain it a bit more. modscan and modsim are programs that i found which simulate modbus devices or simply scan an active modbus communication so that you can see whats going on. the values i mentioned (10001 and stuff) are those that are given to me by labview.if i start a new project with a modbus io server and create some variable bindings i always got those variables. with some of them i can send or gather data from modscan, with some others not!

actually my programs only consist of the variables i get when creating new bindings and for them i got element to show or to to write something to them

[K C]

If you have no progam in Labview you can't have a problem in Labview

It still doesn't make sense to me what you are saying. 

Ok, the Modsim part I understand (that was easy) If you use a Modscanner to  monitor the serial port ?? then it is possible that a other program cannot get control to that port.

Please explain what you are trying to do in Labview

[philipp.n]

my overall quest is to establish a connection between a serial modbus device and labview. in order to learn something about how to work with labview i downloaded modscan what is actually simulating a modbus device via lan and this works. modscan also is able to gain connection to the serial modbus device, but labview doesnt do anything with the serial port.actually it is not sending or recieving any data

[K C]

Did you try my vi in the MB.zip ??

Did you put it in a VI with a configure COM port ?? ( I don't think this was in this VI but I cannot check this at the moment, Don't have LV8 at home  )

Can you post your VI, sometimes this clears up a lot of things.

Tomorrow morning (for me) I look further into it.

[K C]

The VI in this ZIP you can use but you have to modify a few things. It just made to test the ModBus communication for one situation.

[MJBrehm]

https://forums.ni.com/t5/Reference-Design-Content/LabVIEW-Modbus-API/ta-p/3524019

do these still work with Labview 8?

This library was a life saver with my modbus app.

Message Edited by MJBrehm on 06-21-2006 08:39 AM