Debug messages in TwinCAT->Error List

Debugging messages written to the application log facilitate troubleshooting of the system. In order to view the activated debug messages start the TwinCAT XAE and select the View->Other Windows->Error List menue command. A debug output is shown below. The different message types are identified with the respective numbers.

Debug messages in TwinCAT->Error List 1:

Debug messages in TwinCAT->Error List 2:

The messages are activated in different ways (with different parameters) depending on whether you use the "Low-Level" or "High-Level" interface. Below the list of the different parameters.

1. Hexadecimal output of the ASDUs (without link layer control header). 32 ASDU data bytes per row are output as hexadecimal numbers. Bigger frames are split into multiple lines:

Name	ON	OFF	Controlled station		Control station
Name	ON	OFF	Low-Level	High-Level	Low-Level	High-Level
ST_IEC870_5_101TBuffer.eDbg	eIEC870_FIFO_DBG_ALL	eIEC870_FIFO_DBG_OFF	Yes	-	Yes	-
FB_IEC870_5_101Slave.sysPara.dbgMode	IEC870_DEBUGMODE_ASDU	IEC870_DEBUGMODE_DISABLED	-	Yes	-	-
FB_IEC870_5_101Master.sysPara.dbgMode	IEC870_DEBUGMODE_ASDU	IEC870_DEBUGMODE_DISABLED	-	-	-	Yes

2. Hexadecimal output of the APDUs (TCP/IP frames). 32 APDU data bytes per row are output as hexadecimal numbers. Bigger frames are split into multiple lines:

Name	ON	OFF	Controlled station		Control station
Name	ON	OFF	Low-Level	High-Level	Low-Level	High-Level
FB_IEC870_5_101TProtocol.bOutDbg	TRUE	FALSE	Yes	-	Yes	-
FB_IEC870_5_101Slave.sysPara.dbgMode	IEC870_DEBUGMODE_LINKLAYER	IEC870_DEBUGMODE_DISABLED	-	Yes	-	-
FB_IEC870_5_101Master.sysPara.dbgMode	IEC870_DEBUGMODE_LINKLAYER	IEC870_DEBUGMODE_DISABLED	-	-	-	Yes-

3. State change messages:

Name	ON	OFF	Controlled station		Control station
Name	ON	OFF	Low-Level	High-Level	Low-Level	High-Level
FB_IEC870_5_101Slave.sysPara.dbgMode	IEC870_DEBUGMODE_DEVSTATE	IEC870_DEBUGMODE_DISABLED	-	Yes	-	-
FB_IEC870_5_101Master.sysPara.dbgMode	IEC870_DEBUGMODE_DEVSTATE	IEC870_DEBUGMODE_DISABLED	-	-	-	Yes

4: Link layer error messages:

Name	ON	OFF	Controlled station		Control station
Name	ON	OFF	Low-Level	High-Level	Low-Level	High-Level
FB_IEC870_5_101Slave.sysPara.dbgMode	IEC870_DEBUGMODE_LINKERROR	IEC870_DEBUGMODE_DISABLED	-	Yes	-	-
FB_IEC870_5_101Master.sysPara.dbgMode	IEC870_DEBUGMODE_LINKERROR	IEC870_DEBUGMODE_DISABLED	-	-	-	Yes

5. Messages logged from the PLC application (sample).

Further diagnostic tools:

Portmon for Windows (v3.02, Windows Sysinternals);
Diverse protocoll test suite products;