Ping-pong method

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The ping-pong method is a method for transferring data between two communication devices . It can be used in the simplest configuration of a master / slave system with only one slave. The master sends a character and waits for the response from the slave . After receiving the answer, he can send a new character. The ping-pong method has the advantages of a synchronous communication link . The requests from the master are essentially the clock signal for the slave.

Serial connection

The advantage of the ping-pong method arises when it is used as a communication protocol between a personal computer and a terminal device via a serial interface , for example EIA-232 with the lines Rxd, Txd and GND.

With a PC operating system , data can be lost due to buffer overflow when a longer character string is received via the serial interface . This is due to the different execution times of the programs that run on the PC and delay the emptying of the cache. This is avoided with the ping-pong method, since the terminal device only ever sends a sequence of a defined length to the master's request.

The disadvantage of the ping-pong method is the reduced data transmission speed of larger amounts of data, as the repeated requests from the master create a certain communication overhead. This disadvantage can be reduced if the length of the terminal message is large compared to the master request.

The data transmission rate can also be a problem when used in radio interface modules. Many of these modules send data in packets. If the master request is shorter than a data packet , the data transmission rate is greatly reduced if the interface sends a largely empty packet.

Applications

Communication technology

In communication technology, the ping-pong method is used, for example, for the U p0 interface of telephone systems.

IP network

In IP - networks is through the on ICMP anabolic ping - command to connect to other hosts tested. The response data packet that is only sent back in the event of success is also called a pong.

literature

  • Dieter Conrads: data communication. Procedure - Networks - Services. 2nd edition, Friedrich Vieweg & Sohn Verlag, Wiesbaden 1993, ISBN 3-528-14589-7 .
  • Manfred Broy, Otto Spaniol (Hrsg.): VDI-Lexikon Informatik und Kommunikationstechnik. 2nd edition, Springer Verlag Berlin Heidelberg, Berlin Heidelberg 1999, ISBN 978-3-642-46846-9 .
  • Werner Bärwald: Expert practice lexicon communication technologies. Networks - Services - Applications. Expert Verlag, Renningen 2009, ISBN 978-3-8169-2843-0 .
  • Otfried Georg: Telecommunication technology . A practical introduction, Springer Verlag, Berlin / Heidelberg 1996, ISBN 978-3-540-61381-7 .
  • Peter R. Gerke: Digital communication networks. Principles - facilities - systems, Springer Verlag, Berlin / Heidelberg 1991, ISBN 978-3-642-93459-9 .
  • Wolf-Dieter Haaß: Handbook of the communication networks. Introduction to the basics and methods of communication networks. Springer, Berlin Heidelberg 1997, ISBN 3-540-61837-6 .