Special characteristics of DNP3 communication

• Change-driven data transmission
  • Change-driven transmission of process data between RTU and control center
  • Signaling of RTU, control center or connection failure
  • Automatic data updating for all communication partners involved following troubleshooting and following the startup of the RTU or control center
• Chronological processing of process data
  • Time tagging of all data frames at the place of origin allows process data to be archived by the process control system in the correct chronological order
  • The time of the DNP3 stations in the WAN can be synchronized via SIMATIC WinCC (including summertime/wintertime switchover)
• Local data storage
  • The TIM communication module can temporarily store (for several hours or even days) message frames should the connection or the communication partner fail
  • Intermediate storage of message frames of lower priority in the case of priority-controlled data transmission (with dial-up networks or quantity-dependent data transmission costs)

Operating modes

The DNP3 telecontrol protocol supports the following operating modes:

• Polling
• Polling with time slot procedure
• Multi-master polling with time slot procedure
• Spontaneous mode in dial-up networks
• Spontaneous mode in the TCP/IP-based WAN