IEC 60870-6 ICCP/TASE.2 communication protocol

Description
Communication line configuration
Communication line protocol parameters
Communication station configuration
Station protocol parameters
I/O tag configuration
I/O address
Tell commands
Literature
Changes and modifications
Document revisions

Description

IEC 60870 part 6 belongs to the IEC 60870 set of standards that are used for remote control, monitoring, and telemetry in both the telecommunication networks of electric (power) systems and the applications for control of energy centers. IEC 60870-6 standard is based on the functional-profile theory. A description of the functional profiles, their classification, and defining is taken from IEC 60870-6-1.
A profile for the Telecontrol Application Service Element 2 (TASE.2) is known as ICCP - Inter-Control Centre Communications Protocol. TASE.2 in the application layer is defined in the IEC 60870-6-503 standard. This standard defines the protocol of the application layer so that it accomplishes the requirements for functional cooperation. It also defines the requirements for both the presentation and relation layers that TASE.2 provides.
TASE.2 protocol is based on MMS (Manufacturing Message Specification). The basic functions of ICCP are specified as a set of so-called "Conformance Blocks".

In D2000 System, ICCP protocol supports the functions of block 1 and 2:

1. Periodic System Data: Status points, analog points, quality flags, timestamp, change of value counter. Association objects to control ICCP sessions.
2. Extended Data Set Condition Monitoring: Provides report-by-exception capability for the data types that block 1 is able to transfer periodically.

A transmission layer ISO over TCP/IP is implemented according to RFC 1006 specification.

Communication line configuration

• Communication line category: TCP/IP-TCP
• TCP Parameters:
  • Host: string max. 80 characters – server name in INET format (a name or numerical address a.b.c.d) or the text "ALL"
  • Port: TCP port number (0 to 65535), port 102 is used by default.
  • Line number: not used, set 1

If the ICCP connection is initiated by D2000 (the Initiate address parameter), you must enter a valid hostname of the ICCP server according to the above-mentioned rules. If, on the contrary, D2000 accepts the received request for ICCP connection, you must enter the text "ALL" to the Host field. It means that the D2000 System will listen on all interfaces that belong to the particular server (with running D2000 KOM process). If the listening is required only on the particular interface, enter the IP address of this server interface in INET format.
Note: When the D2000 KOM process works as an ICCP Server, it is able to operate more ICCP Clients at the same time.

If D2000 System initiates this connection (the Initiate address parameter), you must also enter the port number on which a target ICCP server listens. The ISO over TCP/IP protocol uses port 102. If D2000 System only accepts the incoming connections, the port number is not used (enter for example 1). The number of bound TCP port is defined by the line protocol parameter "Bind TCP port". This feature enables the operation of ICCP protocol as a client and server simultaneously.

For redundant systems, the user may set more names/addresses separated by a comma. When the connection fails, the communication process will try to reconnect to the server on the given address. If it fails again, the process will try to establish a connection to the next address. It repeats this action cyclically until it establishes the connection with one of the servers.

Communication line protocol parameters

Communication lines - configuration dialog box - tab Protocol parameters.
These parameters influence some optional parameters of the protocol. You can define the following parameters:

Table 1

Note 1

If all debugging info is enabled, it could cause an overload of communication server and a decrease in data transfer rate between the centers. After setting and debugging the communication we recommend you minimize the amount of debugging information.

Communication station configuration

• Communication protocol "IEC 60870-6 ICCP/TASE.2".
• Polling parameters are not used.
• The protocol does not support time synchronization between the control centers.

Station address

Img. No. 1, Station address

Station address configuration (in ICCP terminology - Control Centre) requires to set the following data:

• Control Center type
  • Local Control Center (LCC)
    In LCC, there are only data values that are transmitted to the partner centers. It means, that only the output I/O tags (Ao, Co, Dout) are relevant for this station. If the I/O tag value is changed, by the control objects, data are then published out of D2000 System. In the opposite direction - to LCC, the values can be transmitted by the commands. These objects could be the input values (Ai, Ci, Di, Qi).
    Exactly one station of LCC type must be configured on the line. 
  • Remote Control Center (RCC)
    In RCC, there are only data values that are transmitted from the partner centers to the D2000 System. It means, that only the input I/O tag values (Ai, Ci, Di, Qi) are relevant for this station. The values of output I/O tags are transmitted as commands via RCC from the D2000 System (MMSWriteRequest message).
    One or more stations of RCC type can be configured on the line.  
• Domain
  • For LCC - Local Domain
    It is a domain name that executes the Local Control Center for the remote client (center). The text string is max. 32 characters. It consists of alphanumeric characters ("a…z", "A…Z", and "0…9"), underscore ("_") or dollar sign ("$"). The first sign must be a letter.
  • For RCC - Remote Domain
    It is a domain name that executes Remote Control Center for a local client (D2000). The text string is max. 32 characters. It consists of alphanumeric characters ("a…z", "A…Z", and "0…9"), underscore ("_") or dollar sign ("$"). The first sign must be a letter.

The Browse button, which is enabled only for RCC, enables (if a D2000 KOM process is running and if communication is established) to obtain a list of domains from a remote control center. For browsing functionality to work, the remote control center must support the handling of getNameList request with parameter ObjectClass=DOMAIN.

• Remote Control Centre Parameters
  Permitted only for RCC.
  • Initiate
    It enables an active initiation of TCP connection to the remote control center. It means, D2000 System initiates this connection.
  • Role
    The parameter Service Role belongs to Bilateral Table Agreement. It indicates the ICCP activity that is required for the Remote Control Center - Client, Server, or Client & Server. The value is set according to an agreement with the partner local center. Usually, when enabling the parameter Initiate, you should set a pro-active communication, i.e. Client or Client & Server value.
    If the Initiate parameter is on, a handler task is created for every RCC with Client or Client & Server role and connects to the ICCP server according to the line configuration.
    If the Initiate parameter is off, the D2000 KOM process is waiting for the ICCP client to connect, and according to the station's protocol parameters (TSEL, SSEL, PSEL, AP Title, AE Qualifier) is matching an ICCP client to an RCC with Server or Client & Server roles.

Station protocol parameters

Communication station - configuration dialog box - tab Protocol parameters.
These parameters influence some optional parameters of the protocol. You can set the following station parameters:

Table 2

Note 1

The identification of incoming clients is performed according to all address parameters, i.e. TSEL, SSEL, PSEL, AP Title, and AE Qualifier. If the connected ICCP client provides different address parameters that do not match parameters configured on any RCC-type station configured in the D2000 system, the connection is rejected.

Note 2

So many parameters needed for setting the "Data Set Transfer Set" can seem complicated. To set the RBE (Report By Exception) parameter (i.e. the functionality of "Conformance Block" No. 2, "Extended Data Set Condition Monitoring") is, however, very important.

1. RBE = NO
   Report All object values from Data Set are sent in each Report. After elapsing the "Start Time", the Reports are sent with a period "Interval". The parameter "DS Conditions - Interval Timeout" must be enabled.
2. RBE = YES
   More effective data transmission. Only the changed values are transmitted. After elapsing the "Start Time" timeout, a complete Report with all object values of the Data Set is sent. Thereafter Report is sent after elapsing the "Buffer Time", which contains only changed object values of the Data Set. Report with all object values of the Data Set is sent with the "Integrity Timeout" period. The parameters "DS Conditions - Integrity Timeout", "DS Conditions - Object Change" must be enabled. The parameter "DS Conditions - Interval Timeout" must be set on NO.

I/O tag configuration

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

I/O address

mg. No. 2, I/O tag address (Data Value)

The configuration of Data Values (according to ICCP terminology) requires the following data:

Name

A unique text string that identifies Data Value. The maximum size is 32 characters.
Note: if the I/O tag's address is specified as %IGNORE, such an I/O tag will be ignored.

Data Type

The list of permitted data types:

ICCP Validity is converted to D2000 UniVal as follows:

Valid = Normal, Held, Suspect = Weak, NotValid = Invalid.

A quality flag CurrentSource is ignored when data receiving. When data sending, it is always set on CurrentSource = Telemetered.

Scope

Scope of definition for a Data Value.

• VMD Specific - Data Value is defined on a Virtual Manufacturing Device level
• Domain Specific - Data Value is defined within a specific domain inside a device

Note: The Domain Specific setting was used for communication with the Siemens Sinaut Spectrum system, the VMD Specific setting was used for communication with the OSI Monarch system.

Read Only

Enables only the reading of Data Value, the writing by the command is disabled.

Browse

For I/O tags on a Remote Control Center station, it is possible to query a list of objects and their data types from the ICCP server, if a KOM process is running and if communication is established.
After a Browse button is clicked, an ICCP Browser window is opened and the KOM process starts to query a list of objects using a message GetNameList-Request and thereafter their data types using GetVariableAccessAttributes-Request messages.

Img. No. 3, ICCP Item Browser window

Meaning of individual choices and buttons:

Auto

If this choice is active, the Data Type will be set to Autodetect, otherwise to value discovered during browsing, e.g. StateQ, StateQTimeTag ..

Scope

Sets the scope of browsing - VMD Specific or Domain specific objects will be browsed (the domain is defined in the configuration of RCC).

Copy all to clipboard

Copies the displayed objects and their respective data types into the Windows Clipboard.

Refresh

By pressing the Refresh button it is possible to enforce re-querying of the list of objects from the ICCP server. By default, the KOM process reads the list of objects and their respective data types only during the first browse request (once for VMD Specific and once for Domain specific objects) and stores them in memory. This reading can take a longer time, depending on the number of ICCP objects and the speed of the ICCP server. These cached lists are sent to the CNF process(es), so that consecutive filling of the Browse window is fast.

Filtering in the list of objects

The browse window enables filtering by the object name and data type. It is not necessary to enter the full text in the filter field. The notation "*FILTERED EXPRESSION*" is supported. The symbol * represents any text before and after the expression (e.g. *momen*).

Note 1

Besides the user-defined objects with supported data types (StateQ, StateQTimeTag .. RealExtended) a list of objects can contained pre-defined protocol objects with different types (Bilateral_Table_ID, DSConditionDetected, DSEventCodeDetected, DSTransferSetName, DSTransferSetTimestamp, NextDSTransferSet, Supported_Features, Tase2_Version, Transfer_Report_ACK, Transfer_Report_NACK). These objects cannot be used in I/O tag configuration and they are listed only due to completeness and verification that browsing is functional even when there are no user-defined objects configured on the ICCP server.

Note 2

In the versions from 20th December 2018 and newer, the recycling of browser dialog has been implemented. If the dialog is closed by the Cancel button or after selecting an object, it is actually only hidden and it is available for browsing by another I/O tag within the same station so that the tree structure of the browsed objects is preserved. Clicking on the close icon at the top right corner will cause the dialog to be really closed.

Tell commands

Literature

• RFC 1006 (ISO Transport Service on top of the TCP, Version: 3)
• International Standard ISO/IEC 8073 (Open Systems Interconnection — Protocol for providing the connection-mode transport service)
• International Standard ISO/IEC 8327-1 (Open Systems Interconnection — Connection-oriented Session protocol: Protocol Specification)
• International Standard ISO/IEC 8823-1 (Open Systems Interconnection — Connection-oriented Presentation protocol: Protocol Specification)
• International Standard ISO/IEC 8650-1 (Open Systems Interconnection — Connection-oriented protocol for the Association Control Service Element: Protocol Specification)
• International Standard ISO/IEC 60870-6-503 (Telecontrol protocols compatible with ISO standards and ITU-T recommendations - TASE.2 Services and protocol)
• International Standard ISO/IEC 60870-6-505 (Telecontrol protocols compatible with ISO standards and ITU-T recommendations – TASE.2 User guide)
• International Standard ISO/IEC 60870-6-702 (Telecontrol protocols compatible with ISO standards and ITU-T recommendations – Functional profile for providing the TASE.2 application service in end systems)
• International Standard ISO/IEC 60870-6-802 (Telecontrol protocols compatible with ISO standards and ITU-T recommendations – TASE.2 Object models)

Changes and modifications

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Document revisions

• Ver. 1.0 - March 26, 2012 - Creation of document.
• Ver. 1.1 - May 2, 2017 - Browsing support, Autodetect addresses.