Basic settings: System parameters

The common ASDU address and the user functions of the substation are configured via the system parameters.

In our introduction we configure the following system parameters:

The common ASDU address is set to 7 (asduAddr).

During initialization the system time of the substation is synchronized with the system time of the local TwinCAT PC (bUsePCTime).

Synchronization of the substation system time via the time synchronization command is activated (bSyncTime).

During the synchronization of the system time in the substation, the system time of the TwinCAT PC should not be synchronized (bSyncPCTime).

Sending of M_EI_NA_1 (End of init) to the central station is activated (bEndOfInit).

Sending of the periodic/cyclic data is deactivated (bPerCyclic). The base time for sending of these data is set to 5 s.

Background scan is deactivated (bBackScan). The background scan cycle time is set to 30 s.

Local freeze and resetting of the counter readings is activated (bPerFRZ), and the cycle time for freeze and resetting is set to 15 s.

The logging of the debug messages in the application log is activated (dbgMode). Changes in the device status are logged.

Add the following PLC code to your PLC project:

IF init THEN 
init := FALSE; 
... 
 
server.sysPara.asduAddr := 7; 
server.sysPara.bUsePCTime := TRUE; 
server.sysPara.bSyncTime := TRUE; 
server.sysPara.bSyncPCTime := FALSE; 
server.sysPara.bEndOfInit := TRUE; 
server.sysPara.bPerCyclic := FALSE; 
server.sysPara.tPerCyclicBase := T#5s; 
server.sysPara.bBackScan := FALSE; 
server.sysPara.tBackScanCycle := T#30s; 
server.sysPara.bPerFRZ := TRUE; 
server.sysPara.tPerFRZCycle := T#15s; 
server.sysPara.dbgMode := (*IEC870_DEBUGMODE_ASDU OR*) IEC870_DEBUGMODE_DEVSTATE; 
 
... 
ELSE 
server( pInputs := ADR( inputs ), 
cbInputs := SIZEOF( inputs ), 
pOutputs := ADR( outputs ), 
... 
 
END_IF

The documentation for all system parameters can be found here: ST_IEC870_5_101SystemParams.