ST_IEC870_5_101ProtocolParams

Protocol parameters of the link layer. The meaning of the parameters differs, depending on the protocol or station type.

Syntax

TYPE ST_IEC870_5_101ProtocolParams :
STRUCT
    eType         : E_IEC870_DEVICE_TYPE       := eIEC870_101_SLAVE;
    eLinkReset    : E_IEC870_5_101LinkReset    := eIEC870_LinkReset_CU;
    linkAddr      : DWORD                      := 1;
    eLinkAddrSize : E_IEC870_5_101LinkAddrSize := eIEC870_LinkAddr_TwoOctets;
    eLinkMode     : E_IEC870_5_101LinkMode     := eIEC870_LinkMode_Unbalanced;
    eFrameType    : E_IEC870_5_101FrameType    := eIEC870_FrameType_FT1_2;
    tRxTimeout    : TIME := T#5s;
    tTxTimeout    : TIME := T#5s;
    bForceC1Res   : BOOL := TRUE;
    bForceC2Res   : BOOL := TRUE;
    tClass1Poll   : TIME := T#200ms; 
    tClass2Poll   : TIME := T#200ms;
    nRetries      : BYTE := 3;    
    tRetry        : TIME := T#100ms;
    tResponse     : TIME := T#1s;
    tTestLink     : TIME := T#5s;
    tPollDFC      : TIME := T#1s;
    FRAMELength   : BYTE(MIN_IEC870_5_101Link_FRAMELEN..MAX_IEC870_5_101Link_FRAMELEN) := MAX_IEC870_5_101Link_FRAMELEN;
    bRetainBuffer : BOOL := FALSE;
    tMaxPollDelay : TIME := T#0s;
    tLinkPollCycle: TIME := T#10s; 
END_STRUCT
END_TYPE

The table below contains notes regarding the configuration. It the values are fixed, the parameter must match the value from the table (not configurable).

Key:

X The parameter is used and is configurable;
N/A The parameter is not used and is not configurable;

Parameter name	Initialization value	IEC 60870-5-101 controlled station (slave, unbalanced mode)	IEC 60870-5-101 control station (master, unbalanced mode)	IEC 60870-5-103 control station (master, unbalanced mode)	IEC 60870-5-102 control station (master, unbalanced mode)	Description
eType	eIEC870_101_SLAVE	fixed, eIEC870_101_SLAVE	fixed, eIEC870_101_MASTER	fixed, eIEC870_103_MASTER	fixed, eIEC870_102_MASTER	Configures the protocol and station type.
eLinkReset	eIEC870_LinkReset_CU	N/A	X	X	fixed, eIEC870_LinkReset_CU	Reset type during initialization of the link layer.
linkAddr	1	Own address	Address of the remote device	Address of the remote device	Address of the remote device	Connection address.
eLinkAddrSize	eIEC870_LinkAddr_TwoOctets	X	X	X	X	Octet size of the connection address.
eLinkMode	eIEC870_LinkMode_Unbalanced	fixed, eIEC870_LinkMode_Unbalanced	fixed, eIEC870_LinkMode_Unbalanced	fixed, eIEC870_LinkMode_Unbalanced	fixed, eIEC870_LinkMode_Unbalanced	Connection mode (balanced/unbalanced).
eFrameType	eIEC870_FrameType_FT1_2	fixed, eIEC870_FrameType_FT1_2	fixed, eIEC870_FrameType_FT1_2	fixed, eIEC870_FrameType_FT1_2	fixed, eIEC870_FrameType_FT1_2	Telegram frame format. Currently only the format F1.2 is supported.
tRxTimeout	T#5s	X	X	X	X	Max. frame receive timeout time.
tTxTimeout	T#5s	X	X	X	X	Max. frame send timeout time.
bForceC1Res	TRUE	X	N/A	N/A	N/A	If this parameter is set (TRUE), Class 1 data are sent as response to a Class 2 request, if Class 1 data are available (optimized, higher data throughput for Class 1). If this parameter is not set (FALSE), a negative response is sent to a Class 2 request, if Class 1 data are present (lower data throughput, empty telegrams).
bForceC2Res	TRUE	X	N/A	N/A	N/A	If this parameter is set (TRUE), Class 2 data are sent as response to a Class 2 request, even if Class 1 data are available (optimized, higher data throughput for Class 2). If this parameter is not set (FALSE), a negative response is sent to a Class 2 request, if Class 1 data are present (lower data throughput, empty telegrams)
tClass1Poll	T#200ms	N/A	X	X	X	Cycle time in which the Class 1 data are to be queried (unbalanced mode only).
tClass2Poll	T#200ms	N/A	X	X	X	Cycle time in which the Class 2 data are to be queried (unbalanced mode only).
nRetries	3	Not used up to v3.0.6 (error on first disturbed frame), configurable from v3.0.8 or higher	X	X	X	Maximum number of telegram retries when the data exchange fails.
tRetry	T#100ms	N/A	X	X	X	Delay time for telegram retries when the data exchange fails.
tResponse	T#1s	N/A	X	X	X	This parameter determines the maximum delay time for a telegram acknowledgement. If this time is exceeded, the telegram is repeated up to nRetry times.
tTestLink	T#5s	N/A	N/A	N/A	N/A	Cycle time in which the test telegrams are to be sent (balanced mode only)
tPollDFC	T#1s	N/A	X	X	X	Cycle time in which the connection status is to be queried, if the DFC bit is set. The DFC bit is set by the remote device if further telegrams could cause an overflow.
FRAMELength	MAX_IEC870_5_101Link_FRAMELEN	X	X	X	X	Telegram length, max. length L.
bRetainBuffer	FALSE	from product version v3.0.2 or higher	X	X	X	If this parameter is set, the internal TX/RX buffers are not reset (deleted) on initialization of the link layer.
tMaxPollDelay	T#0s ( = 0: deactivated, <> 0: active)	from product version v3.0.2 or higher	N/A	N/A	N/A	The connection status is declared OFFLINE, when this time is exceeded in the absence of poll queries.
tLinkPollCycle	T#10s	N/A	X	X	X	Cycle time in which link status telegrams are sent to the substation if there is no connection.

Additional information for bForceC1Res and bForceC2Res parameters:

Irrespective whether you set both parameters, one of them or none of them, the ACD bit is set accordingly in order to notify the control station whether Class 1 or Class 2 data should be queried next. These parameters only influence the behavior of the substation for Class 2 interrogations.

Requirements

Development environment	Target system type	PLC libraries to be linked (category group)
TwinCAT v3.1.4012.0	PC oder CX (x86, x64, ARM)	Tc2_IEC60870_5_10x (Communication->IEC60870) Tc2_SerialCom (Communication->Serial) Tc2_TcpIp (Communication->TcpIp) Tc2_Utilities (System)