IEC 870-5-104 Sinaut communication protocol

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

Supported device types and versions

The protocol is a modification of the protocol IEC870-5-104 working on the basis of TCP network communication. The protocol has been modified specifically for redundant communication with the system Siemens Sinaut Spectrum. It supports the balanced mode and active and passive establishing the communication (connecting party and listening party) according to the station protocol parameters, and therefore allows to interconnect not only D2000 system with Sinaut system but also two D2000 systems.

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

The picture above shown TCP connections - each process D2000 KOM(D2000 Hot, D2000 StandBy) with eachSinaut (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. Foe each station on one line, there must be defined different ASDU address.
  Note: Because of Sinaut data model, the low and high address bytes are changed unlike the standard IEC 104 implementation, i.e. big endian instead of little endian.
  Example: 
  station address=1, ASDU address is sent as 0, 1 bytes
  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 Sinaut data model, the low and high address bytes are changed unlike the standard IEC 104 implementation, i.e. big endian instead of little endian.
  Example:
  I/O tag address=1, ASDU address is sent as 0, 0, 1 bytes.
  I/O tag address=66051(1*65536+2*256+3), ASDU address is sent as bytes 1, 2, 3.
  For better orientation, 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.

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

Table 1

Note: The individual bites of the byte that inform us on quality (SIQ for ASDU 1,2,30; DIQ for ASDU 3,4,31; QDS for 5..14,20,32..36) are mapped to the flags FLA (0.bit),FLB (1.bit) ..FLH (7.bit).
For example:
for ASDU 4: FLA=DPI bit 0, FLB=DPI bit 1, FLC=0, FLD=0, FLE=BL bit, FLF=SB bit, FLG=NT bit,FLH=IV bit.
for ASDU 16: FLA..FLE Sequence number bity 0..4, FLF=CY bit, FLG=CA bit, FLH=IV bit

Moreover:

• if a bit is set to IV (Invalid), the value state will be Invalid
• if some of the bits are set to NT (Not topical), SB (Substituted), BL (Blocked), OV (Overflow), CA (Counter adjusted), CY (Counter overflow) for corresponding ASDU types, the value state will be Weak.

* - T-bit of the value of these ASDUs is in the flag FI, a number within -64 .. +63 is in a variable of Ci/Ai type

** - ASDU 17 and 38: SEP byte is in the flags FLA (0.bit),FLB (1.bit) ..FLH (7.bit), 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 course (from D2000 system to Sinaut system and vice-versa in balanced mode):

Table 2

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

When sending commands (ASDU 45-64), the value of 6 [Activation] is used as CauseOfTransmission. Expecting a response from the controlled station depends on the parameter CMDC. There are the following possibilities:

• write is successful, if there is a packet with RSN confirming the SSN packet with the log
• write is finished, if there is a response with CauseOfTransmission=7 [Activation Confirmation] and/or 10 [Activation Termination]. Success/Unsuccess depends on the setting of the P/N bite in CauseOfTransmission.

Redundant communication with Siemens Sinaut system -  Basic features:

• One communication line of CP Redundant type communicates with two redundant partners Sinaut, where one of them is HOT, the other is STANDBY.
• Communication to each of the partners is performed through two redundant networks (i.e. there are created two TCP connections for each Sinaut, together four TCP connections).
• Sending new values and replying to ASDU 100 [Interrogation Command] is allowed just HOT partner (D2000 eventually Sinaut). Having established the connection, STANDBY partner only sends confirmations (S-frames) and test frames. STANDBY partner may also send ASDU 100 [Interrogation Command].
• Each partner communicates to the other just through one TCP connection. It sends new values, command confirmations, ASDU 1000 and replies to ASDU 100 through the connection. Second connection is standing (except sending test frames through it) and is used when a failure on first connection is detected.

Establishing connection:

• In the active mode, the process D2000 KOM connects to specified TCP ports. It sends to each of the ports an U-frame StartDT Act, and waits for StartDT Con as reply.
• In the passive mode, the process D2000 KOM waits on specified TCP port (see the parameters SP, SH). When the clients are connected, the process waits for an U-frame StartDT Act, and sends StartDT Con as reply.
• Further communication is completely symmetrical one. Both partners can send ASDU 100 [Interrogation Command] in order to read all current values and then the partners receive and sends 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 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 ASDUAddres=FFFF
• receiving the current values of all I/O tags
• receiving an I-frame with ASDU 100 [Interrogation Command] and with CauseOfTransmission= 10 and ASDUAddres=FFFF

Forced disconnection: If all communication stations on the line are in the simulation mode or the communication is disabled for them, the communication line will be disconnected (closing communication sockets). If the simulation mode is not enabled and communication is not disabled for at least one station (the tab Parameters of object of Station type), the line will be reconnected (and Interrogation Command eventually Counter Interrogation Command will be send to the station). Then after enabling each next station, there is send an Interrogation Command or Counter Interrogation Command to the station; see the next point.

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

The protocol IEC870-5-104 Sinaut supports the balanced mode described in the communication protocol IEC 870-5-104 - it is server in part, so the rules of  server protocols are valid for it.

Communication line configuration

• 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, where the process D2000 KOM is connecting to.
    In the passive mode (see the parameters SP, SH), they are the IP addresses of a client, which are accepted by the process D2000 KOM (if the client is connecting from other IP address, will be disconnected).
  • Port: TCP port number (0...65535)
    In the active mode, it is the server port, where the process D2000 KOM is connecting to.
    In the passive mode (see the parameters SP, SH), the parameter will be ignored (but must be set, e.g. to the value of 0).
  • Line number: is used as Originator ASDU address (1 byte, 0-255).

Communication station configuration

• Communication protocol: IEC870-TCP Sinaut.
• Station address is a decimal number within the range of 0 až 65535, defines the ASDU address.
  For better orientation, 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 ASDU address.

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

Station protocol parameters

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

Table 3

The defined parameters, except for Order of IC and Order of Counter IC, are valid for the entire line, i.e. they can be set only for one station on the line.

ICCP compatible flag mapping

A status byte of ASDU, unlike ICCP OPC communication, enables the transmission only limited group of flags. In Table 4 you can see a conversion of bits of the status byte to the flags which are compatible with ICCP OPC communication.

Table 4

IO tag configuration

Permitted I/O tag types: Ai, Ao, Ci, Co, Di, Dout, Qi

• I/O tag address is mapped to Information object address, i.e. contains 3 bytes and must be within the interval of 0...16777215.
  For better orientation, I/O tag address may be defined in the form of ByteHI,ByteMIDDLE,ByteLO, i.e. address 1,2,3 is the same as 66051 (1*256*256 + 2*256 + 3). See a note about IOA address .
• Input I/O tags must have corresponding types (Ai, Ci, Di, Qi) for received ASDU, see the table 1.
• For particular type of output I/O tag (Ao, Dout, Co), it is necessary to set an type of ASDU that should be used, see the table 1 and table 2.
• It is possible to configure one input I/O tag and more output I/O tags on the same address, while the output I/O tags have different ASDUs. Example:
  • I/O tag M1, Di type, address 1,
  • I/O tag M2, Dout type, address 1, ASDU 1 (single-point information)
  • I/O tag M3, Dout type, address 1, ASDU 45 (single command)
  
  Configuration on partner's side:
  • I/O tag P1, Dout type, address 1, ASDU 1 (single-point information)
  • I/O tag P2, Di type, address 1
  
  Writing into the I/O tag P1 from the partner's side gives a new value to the I/O tagM1. Writings of the I/O tags M2, M3 gives a new value to the I/O tag P2on the partner's side.

Literature

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Document revisions

• Ver. 1.0 – December 15th, 2004
• Ver. 1.1 – February 21st, 2011