How to use the telnet command line in Labview

[Wilmer_S]

Hi, someone can help me, I need to use a Telnet session in Labview but without using the http protocol, in this application I can only access the Telnet session using command line, here is an example of how I can access:

1. From my computer, click on Start, then Run and then type in CMD.
2. In the command line enter “telnet 192.168.0.1 5454” (without the quote marks) to bring up a blank DOS screen with a blinking cursor.
3. Type “AT” and press the ENTER key, you should receive an “OK” response.
4. Type in capital letters “AT+CMAR=1234” (without the quote marks)

[candidus]

You have to use the "System Exec.vi". Look at "examples/comm/Calling System Exec.vi" for examples how it can be used.

[Rod42]

Or if you have the Vi's concerned [I think they're in the internet toolkit - search for Telnet on your functions pallete to see if you have them installed],

establish your connection with Telnet open connection (on address 192.168.0.1, port 5454)

read and write as needed with Telnet Read / Telnet Write

when you're done use Telnet Close Connection

(or maybe use Telnet Play Script for your entire conversation, instead of the individual read and write)

Rod.

Message Edited by Rod on 16/06/2010 17:59.. 05:59 PM

Message Edited by Rod on 16/06/2010 18:01.. 06:01 PM

[Wilmer_S]

(or maybe use Telnet Play Script for your entire conversation, instead of the individual read and write)

Hi Rod, can you give me a sample?

[RTSLVU]

I had a similar situation and here is what I did...

In MAX (Measurement and Automation eXplorer)

Select Devices and Interfaces

Select VISA TCP/IP Resources

Create a new resource

Select Manual Entry of Raw Socket

Enter the IP address and port (23 is the standard telnet port)

Give it a name. (VISA Ailas)

Now this "Device" will show up in the VISA drop down just like any other VISA device.

Use the VISA read and write just like you were communicating through a com port.

Since Telnet does not have a stop bit like serial, make sure you enable the termination character.

On your VISA reads set the number of characters to a big number, then VISA will read until it gets the termination character.

See my attached snippet of my Telnet read vi

Message Edited by RTSLVU on 06-16-2010 01:49 PM

Message Edited by RTSLVU on 06-16-2010 01:50 PM

[smercurio_fc]

That's quite clever.

[Wilmer_S]

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That's quite clever. ~

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You have said!! 

[Dennis_Knutson]

I'm sure you could use the TCP/IP functions in the same manner except you would not need to do anything in MAX. After all, that is what the Telnet functions use when you dig down a bit.

[altenbach]

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Dennis Knutson wrote:

I'm sure you could use the TCP/IP functions in the same manner except you would not need to do anything in MAX. After all, that is what the Telnet functions use when you dig down a bit.

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 If you use plain TCP/IP, you need to do the telnet negotiations yourself. 🙂

[RTSLVU]

My first instinct was to use the TCP/IP functions but I abandoned them for the VISA route.

I can't remember exactly why bit I think altenbach is eluding to what I was thinking at the time.