Hello everybody,

We have a problem regarding command execution in ABB RTU 560A. The system and command details:

1. Protocol used is 104 between Control center and RTU.
2. Command type 48 (Analog setpoint Normalized).
3. Cause of transmission is 6.

When we send analog set-point command from SCADA SYSTEM (automatic generation control (AGC)) to power generation plant, the telegram trace shows that during a command processing and before the actcon "activation confirmation", the RTU rejects any other new command (negative activation confirmation).

 

We have EXACTLY the same problem in our grid system (NECSudan) where the AGC is required to control seven hydro units. However, out of the seven AGC setpoint telegrams sent simultaneously, it seems that the RTU (ABB RTU560) processes only one and dumps the other six! Will appreciate any feedback on this frustrating problem....