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 clock 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.
• Logging of debugging 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.