IEC 60870-5-104 Sinaut communication protocol

Supported device types and versions
Communication line configuration
Communication station configuration
Station protocol parameters
I/O tag configuration
Tell commands
Literature
Document revisions

Supported device types and versions

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The protocol is a modification of the IEC 870-5-104 protocol working on the basis of TCP network communication. The protocol has been modified specifically for redundant communication with the Siemens Sinaut Spectrum system. It supports the balanced mode and both active and passive establishment of the communication (a connecting party and a listening party) according to the station protocol parameters and therefore allows to interconnect not only the D2000 system with the Sinaut system but also two D2000 systems.

Picture: the D2000 redundant system communicating with Sinaut redundant system in a redundant network

The picture above shows TCP connections - each process D2000 KOM (D2000 Hot, D2000 StandBy) with each Sinaut (Sinaut Hot, Sinaut StandBy)

Implementation according to the standard IEC870-5-104 is following:

• Originator ASDU address - is 1 byte, it is defined as a line number.

• ASDU address - is 2 bytes, it is defined as station address. For each station on one line, a different ASDU address must be defined.
  

  Note: Because of the Sinaut data model, the low and high address bytes are exchanged (in contrast to the standard IEC 104 implementation), i.e. a big-endian instead of a little-endian is used.
  Example: 
  station address=1, ASDU address is sent as bytes 0, 1
  station address=513 (2*256+1), ASDU address is sent as 2, 1 bytes
  For better orientation, station address may be defined in the form of ByteHI, ByteLO, i.e. address  2,1 is the same as 513

• Cause of transmission - is 2 bytes (it also contains Originator ASDU address)

• Information object address - 3 bytes, it is defined as I/O tag address
  

  Note: Because of the Sinaut data model, the low and high address bytes are exchanged (in contrast to the standard IEC 104 implementation), i.e. a big-endian instead of a little-endian is used.
  Example:
  I/O tag address=1, ASDU address is sent as bytes 0, 0, 1.
  I/O tag address=66051(1*65536+2*256+3), ASDU address is sent as bytes 1, 2, 3.
  For better orientation, the I/O tag address may be defined in the form of ByteLO, ByteMIDDLE, ByteHI, i.e. address 1,2,3 is sent as bytes 1, 2, 3.

The following ASDU types in the monitoring direction (from Sinaut system to D2000 system and also vice-versa in balanced mode) are implemented:

Table 1

Note: Individual bits of the quality byte (SIQ for ASDU 1,2,30; DIQ for ASDU 3,4,31; QDS for 5..14,20,32..36) are mapped to the flags A (bit 0), B (bit 1) .. H (bit 7).
For example:
for ASDU 4:  A=DPI bit 0, B=DPI bit 1, C=0, D=0, E=BL bit, F=SB bit, G=NT bit, H=IV bit.
for ASDU 16: A..E = Sequence number bits 0..4, F=CY bit, G=CA bit, H=IV bit

Moreover:

• if IV (Invalid) bit is set, the value status will be Invalid

• if any of NT (Not topical), SB (Substituted), BL (Blocked), OV (Overflow), CA (Counter adjusted), CY (Counter overflow) bits are set for corresponding ASDU types, the value status will be Weak.

* - T-bit of the value of these ASDUs is mapped to the I flag, a number in range -64 .. +63 goes to a variable of Ci/Ai type

** - ASDU 17 and 38: SEP byte is in the flags A (bit 0), B (bit 1) .. H (bit 7), following 2 bytes (CP16Time2a) are in a variable of Ci/Ai type as a positive number (0-60 000) or they are in a variable of TiR type as a relative time (0-60 seconds)

The following ASDU types are implemented in the control direction (from D2000 system to Sinaut system and vice-versa in balanced mode):

Table 2

To set the bits of the "status" byte (SCO for ASDU 45,58; DCO for ASDU 46,59; RCO for ASDU 47,60; QOS for ASDU 48..50,61..63), flags A (bit 0), B (bit 1) .. H (7.bit) are used except the bits, which are directly set by the variable value ( SCO bit 0, DCO and RCS bits 0-1). Having received a response (positive/negative), the A .. H flags are set according to the bits of the "status" byte.

When sending commands (ASDUs 45-64), the value of 6 [Activation] is used as CauseOfTransmission. Whether a response is expected from the controlled station depends on the CMDC parameter. These options are available:

• Writing is considered successful if a packet with RSN confirming the SSN packet with the write command is received.

• Writing is considered finished if a response with CauseOfTransmission=7 [Activation Confirmation] and/or 10 [Activation Termination] is received. Success/failure depends on the setting of the P/N bit in received CauseOfTransmission.

Redundant communication with Siemens Sinaut system -  basic features:

• One communication line of a TCP/IP-TCP Redundant type communicates with two redundant Sinaut partners, one of them is HOT, the other is STANDBY.

• Communication with each of the partners is performed via two redundant networks (i.e. two TCP connections are created for each Sinaut, so altogether there are four TCP connections by every D2000 KOM process).

• Only the HOT partner (D2000 or Sinaut) is allowed to send new values and reply to ASDU 100 [Interrogation Command]. Having established the connection, the STANDBY partner only sends confirmations (S-frames) and test frames. However, the STANDBY partner may also send ASDU 100 [Interrogation Command].

• Each participant communicates with a partner through a single TCP connection. It sends new values, command confirmations, ASDU 100, and replies to ASDU 100 through this connection. The second connection is not used (except for sending test frames) and it is only used when a failure on the first connection is detected.

Establishing a connection:

• In the active mode, the D2000 KOM process connects to specified TCP ports. It sends a StartDT Act U-frame to each of the ports and waits for StartDT Con reply.

• In the passive mode, the D2000 KOM process waits on a specified TCP port (see the SP, SH parameters). When the clients are connected, the process waits for a StartDT Act U-frame and sends a StartDT Con reply.

• Further communication is completely symmetrical. Both partners can send ASDU 100 [Interrogation Command] in order to read all current values and then the partners receive and send changed values and commands.

Having established the connection, a partner may send I-frame with ASDU 100 [Interrogation Command] with CauseOfTransmission=6 [Activation] and with ASDUAddres=FFFF, whereby it requests the values of I/O tags for all stations. As a replay, the partner waits for:

• receiving an I-frame with ASDU 100 [Interrogation Command] and with CauseOfTransmission=7 and ASDU Address=FFFF

• receiving the current values of all I/O tags

• receiving an I-frame with ASDU 100 [Interrogation Command] and with CauseOfTransmission=10 and ASDU Address=FFFF

Forced disconnection: If all communication stations on the line are in the simulation mode or the communication is stopped for them, the communication line will be disconnected (communication sockets will be closed). When the simulation mode is turned off or the communication is enabled for at least one station (the Parameters tab of the Station type object), the line will be reconnected (and Interrogation Command and/or Counter Interrogation Command will be sent to this active station). Then, when other stations are enabled, the Interrogation Command and/or Counter Interrogation Command is sent to this station; see the next point.

Forced sending of Interrogation Command or Counter Interrogation Command: If a station is not in the simulation mode and the communication is not disabled (the Parameters tab of the Station type object), the D2000 KOM process sends Interrogation Command and/or Counter Interrogation Command (see the OIC and OCIC parameters).

The IEC870-5-104 Sinaut protocol supports the balanced mode described in the communication protocol IEC 870-5-104 - it is partly a server, so it must comply with the rules of server protocols.

Communication line configuration

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• Communication line category: TCP/IP-TCP Redundant

• TCP parameters:

  • Host: string containing at most 80 characters – two comma-separated server IP addresses in the form of a.b.c.d
    In the active mode, they are the addresses of the server, to which the D2000 KOM process is connecting.
    In the passive mode (see the parameters SP, SH), they are the IP addresses of clients, which are accepted by the D2000 KOM process (if the client is connecting from other IP address, it will be disconnected).

  • Port: TCP port number (0...65535)
    In the active mode, it is the server port, where the D2000 KOM process is connecting to.
    In the passive mode (see the SP, SH parameters), the parameter will be ignored (however it must be specified, set it e.g. to 0).

  • Line number: it is used as Originator ASDU address (1 byte, 0-255).

Communication station configuration

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• Communication protocol: IEC870-TCP Sinaut.

• The station address is a decimal number within the range of 0 až 65535, it defines the ASDU address.
  For better orientation, the station address may be defined in the form of ByteHI, ByteLO, i.e. address 2,1 is the same as 513 (2*256 + 1). See a note about the ASDU address.

Note: The protocol supports sending long timestamps (CP56Time2a tag) in local time or UTC time with defined offset (see the Use monotonic UTC time+ parameter ).

Station protocol parameters

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Station configuration dialog box - tab Protocol parameters.
They influence some of the optional protocol parameters. The following station protocol parameters can be defined:

Table 3