====== SSCP protocol ======

Mervis controllers support full configuration and communication via SSCP protocol. Detail description of this protocol is available in: {{:cs:mervis-ide:sharkprotocolspecification_user_2017_05_30.pdf|SSCP description}}.

===== Basic features =====

  * Protocol is defined on application layer
      * TCP and serial bus implementations are currently available. UDP is used for autodetection and configuration.
  * Simple structure of communicated data packets
      * Easy to calculate packet size from header.
      * Extra headers and suffixes can be added for different communication layers - inner structure stays untouched.
      * Each data packet (except broadcast packets) carries information about destination address (8 bit slave ID). Only controller with that address is expected to respond.
  * SSCP can be used for any and all communication tasks
      * Communication of statistics, configuration, PLC detection, communication of values, remote debugging etc.
  * Communication buffer size can be negotiated by client
  * Client authentication is required.
  * [[en:mervis-proxy:00-start|Mervis Proxy]] support.
  * Protocol versioning is supported. Newer version is backward compatible with previous version but usage of deprecated and obsolote methods is not recommended.

===== Communication of Values =====

  * SSCP protocol supports long memory blocks. If the size of the buffer is not sufficient - multiple reads can be made and atomicity of the operation is guaranteed.
  * Every variable is identified by its communication ID.
  * Value is communicated as a block of memory. Offset and length can be used to read part of the larger data structure (array, struct, function block, ...)
      * Memory data layout follows standard rules of data alignment (1-8 bytes)

===== .NET SDK =====

  * There is a SDK with .NET libraries. You can download it {{ :en:mervis-ide:30-communication-protocols:netsscpsdk.zip |here}}.