P6008

The P6008 protocol is a proprietary software product developed by the Italian company Nuovo Pignone (now GE) which enables the coupling of  Nuovo Pignone RTUs with their control systems.

Telegrams can be encoded in binary mode. In practice, binary code is hardly ever used as this causes problems with respect to the modem control lines making it difficult to connect standard PCs. Handshake signals are used to enable efficient recognition of the end of data frames.
In addition there is also the ASCII mode as it was called by Nuovo Pignone. This has nothing whatsoever to do with the ASCII operation mode (STX, ETX...) employed for instance in the ANSI X3.28 protocol. Instead it merely converts and blows up the data volume to twice its size. This does not result in improved timing and end recognition for the reception of data frames.

The data exchange places a heavy workload on the bandwidth and makes use of a rather unconventional solution. There is no spontaneous automatic transmission of data changes, these have to be read out after the respective status messages. Basically, there are 2 request modes: All information can be read out cyclically after a general poll. Or, in order to minimize the burden on the transmission lines, it is better to evaluate the status messages from the RU and then request specific data blocks.

The control station determines which communication mode is applied, it also initiates the complete initialization of the RTUs and the configuration of data point-specific parameters in the RTUs.