How can I control instrument using its RS232 port in VB or VC++?

[KevinShen]

1)How can I control instrument using its RS232 port in VB or VC++?
2)What's the module or .h file need I add-in to VB or VC++?
3)Can you provide me some easy examples for that?

Thanks!

[Chris Matthews]

If you are a Measurement Studio or ComponentWorks user (which is what this forum is for) we provide an ActiveX control for Serial communication that can be used in VB and VC++. You can also use our VISA C++ classes or ActiveX control for serial communication in Measurement Studio. If you are not a Measurement Studio or CW user, then you will have to use Microsoft's compiler provided method to talk to the serial port. You can find help for these methods on http://msdn.microsoft.com/.

As for examples, there are Measurement Studio serial examples for VB can be found in your \MeasurementStudio\VB\Samples\Instr directory.

Best Regards,

Chris Matthews
Measurement Studio Support Manager

[jknight_ve]

hi , i know how to receive data through the serial port using cwserial but i don't know how to send data i need to learn how to do this for my project because i have to send data firts and then the controller will give me data with the information that i need to read or maybe write. i would appreciatte all the help you could give me
Tomás Estrada

[pBerg]

Howdy,

You can find some ANSI C examples of serial communication that install with NI-Serial. They install to C:\Documents and Settings\All Users\Documents\National Instruments\NI-VISA\Examples\C on a Windows XP system. I think that checking out the example(s) would be a great place to start.

[jknight_ve]

i want to know to send data to a serial port with visual basic 6 using the activeX cwserial, im downloading what you posted to see it now , but if someone know how to send data to serial port using activeX (CW) using Visual Basic 6 i will apprecciate your help
regards Tomás Estrada
PD: sorry for my english


Message Edited by jknight_ve on 03-15-2008 11:55 AM

[NestorG]

Hi jknight_ve,

Measurement Studio for Visual Studio 6 includes a VB6, cwserial example.
You may find the example at: <C>:\Documents and Settings\All Users\Documents\National Instruments\MStudioVS6\VB\Samples\Instr\Basic Serial

[jknight_ve]

Thanks Nestor for that example that was what i was looking for, now i have another question how can i make a txt from visual basic and save there data from the program in VB6?

Tomás Estrada


Message Edited by jknight_ve on 03-29-2008 03:25 PM

[NestorG]

No problem Tomás.

You may try using the FSO objects, such as:

Private Sub Command1_Click()

Dim fso, txtfile
Set fso = CreateObject("Scripting.FileSystemObject")
Set txtfile = fso.CreateTextFile("c:\test.txt", True)
' Write a line
txtfile.Write ("This is a test. ")
' Write a line with a newline character.
txtfile.WriteLine ("Testing 1, 2, 3.")
txtfile.Close

End Sub

This is pretty much a generic VB6 question. Simply search online for this topic and you will find tons of info/examples.

For example, MSDN goes into detail using the FSO objects: http://msdn2.microsoft.com/en-us/library/aa263346(VS.60).aspx

[jknight_ve]

thanks nestor that was really helpful now i have another question see, im trying to comunicate with a groups of UDC 3000 (Universal digital controller) using visual basic, now when i send  the data the controller send me for example this data "010004,120,HH" how can i parse that data? knowing that the first 6 digits could change depeding of the response of the controller, this is important for my program because that value of "120" is the value that i asking to read(let's say Set point or the temperature) so i need to separate that message and show in a "isevensegment"

Tomás Estrada

[jknight_ve]

and another question i was looking this example http://zone.ni.com/devzone/cda/tut/p/id/3759 and copy exactly the fist example of parse the data and the code in the part:

Option Explicit
Dim Response As Variant
Dim data As String
Private Sub btnParseString_Click()
data = "@@@002ACK;"
Response = Comm.Tasks("ACK").Parse(data)
Text1.Text = Response(0)
Text2.Text = Response(1)
End Sub

in the red part it say's " error type dismatch " why is that? , i did the parse exactly like in the figure...
Tomás estrada