Ethernet protocols under RTOS-UH

RT-LAN is a program package under RTOS-UH for Communication via Ethernet with computers of other operating systems or RTOS-UH computers. The RT-LAN places under RTOS-UH one I/O task, which supports various protocol services. The connection to the hardware driver depending on the target hardware used is done via the RTOS-UH-own communication mechanisms.

Here you find information about CANopen®-Master/Slave or DeviceNet® Slave.


The Ttransmission Control Pprotocol is used for secure communication via a network. As an extension to UDP, all data packets are monitored for exchange and/or loss. For the programming languages ANSI-C and PEARL90 common under RTOS-UH, function interfaces for addressing the TCP are provided.


The User Datagram Pprotocol is used for data communication of different programs via the network. A programming interface for ANSI-C and PEARL90 is available for this purpose. UDP does not check the exchange or loss of individual packets during the transmission of data.


The File Transfer Pprotocol is used to transfer files over a network. FTP works using the CLIENT-SERVER principle:

  • The FTP SERVER provides the network with access functions to the file system of the local computer.
  • The FTP-CLIENT is a command interpreter that can access external file systems via the network. It can be used to perform file operations between the FTP SERVER addressed via the network and the FTP CLIENT.

The FTP protocol provides functions for transferring and deleting or renaming files or directories.


The Telnet program package for RTOS-UH enables login to or from external systems via the network using a standardized protocol:

  • the Telnet-SERVER provides a user interface with up to 5 network accesses simultaneously for external systems
  • the Telnet-CLIENT enables RTOS-UH systems to access third-party systems

The corresponding counterparts, client or server, must be available on the external systems.


The SMB program package for RTOS-UH connects PC file manager and the RTOS-UH file system via network. Operations on the RTOS-UH file system can be performed from the file manager using the mouse; RTOS-UH can access files on a PC via the Windows network.


The web server allows access to the RTOS-UH computer via a standard browser. In addition to storing static HTML pages on the server, it is also possible to generate dynamic pages using your own PEARL90 programs. Its small footprint of 30-100 KB makes it ideal for systems with little memory.

OSI-Sinec H1

The OSI protocol allows RTOS-UH to be connected directly to a SINEC-H1 network. SINEC-H1 is an Ethernet-based bus system developed by Siemens for communication with Siemens-S5/S7-PLC. RTOS-UH supports OSI layer 4 communication.

Sinec S7

The TCP protocol according to RFC 1006 is available for communication with the S7.


The Process Field Bus is a deterministic fieldbus standardized according to EN 50170 for communication at cell level. It is based on the real-time, asynchronous token bus principle and allows both multi-master and master/slave communication. The data rate is up to 12 MBaud with cost-effective 3-wire RS485 cabling. A DP-Slave implementation with the SPC3-Asic is available.

Further Protocols

Further protocols (e.g. for communication with Allen Bradly SPS) are available. Please contact us (if you activate Javascript, you will find an e-mail address here) if required.

You will find suitable hardware e.g. in our family of protocol couplers.



RTLAN Brochure