Archived:Tools for Using Telnet, SSH, RLOGIN, or RAW TCP With NI Software

Issue Details

• What are the Telnet, SSH, RLOGIN, or RAW TCP protocols?
• Are Telnet, SSH, RLOGIN, or RAW TCP protocols supported in NI Software?
• How do you use these to communicate in a LabVIEW, LabWindows/CVI, or TestStand application?
• Can I call PuTTY/Plink commands from LabVIEW? 

Solution

NI software currently does not come with any native support for creating built-in Telnet, SSH, RLOGIN, or RAW client functionality in your applications. The LabVIEW Internet Toolkit is obsolete as of August, 2014. Certain APIs, specifically the Telnet API, have been deprecated.

The following third-party software allows networked communication: (Disclaimer: Third-Party Add-Ons for LabVIEW are offered by independent third-party providers who are solely responsible for such products. NI shall have no responsibility whatsoever for the performance of the Third-Party Add-Ons). 
 

• The labSSH Toolkit from Labwerx adds Native SSH, SCP, and SFTP support to LabVIEW. labSSH allows you to interact with a remote computer using a secure shell, transfer files, and manage remote file systems with a built in VI library.
• The LabSSH library from Labvolution adds SSH support for communication with remote machines in LabVIEW. 
• The LIBSSH2 for LabVIEW adds SSH client support to LabVIEW using the libssh2 library. However, this only adds client-side SSH support, and does not add SSH server support.

• The PuTTY software package also has a command-line interface to the PuTTY back ends named Plink that can be easily used by LabVIEW, LabWindows/CVI, or TestStand. To do so in LabVIEW, dynamically build a data script file that you can pass to Plink (PuTTY) via its command line options. Then, communicate with and launch the plink.exe executable:
  • In LabVIEW, use the System Exec VI, which is accessible from the Functions Palette by selecting Connectivity » Libraries&Executables
  • In CVI, use the LaunchExecutable() function
  • In TestStand, use the Call Executable step type

Additional Information

Background on Telnet, RLOGIN, SSH, and PuTTY:

• The Telnet protocol offers a way to remotely access multi-user terminal servers across networks and the Internet. Telnet consists of a client-server connection where an application either is the Telnet client or communicates through a separate Telnet terminal client to the multi-user terminal server. 
• RLOGIN is a Unix software utility that allows users to log in on another host via a network, communicating via TCP.  However, neither RLOGIN nor Telnet is a secure protocol, and their traffic can be easily seen with any port sniffing application. 
• Secure Shell or SSH and RAW TCP are network protocols that allows data to be exchanged using a secure channel between two networked devices. Used primarily on Linux and Unix based systems to access shell accounts, SSH was designed as a replacement for Telnet and other insecure remote shells, which sent information, notably passwords, in plaintext, leaving them open for interception.
• To transmit data using any of these protocols, you can use a separate terminal client like "PuTTY", a freeware SSH and Telnet client package that allows you to pass it data via command line options or port forwarding so that it may transmit your data to the multi-user terminal server for you.