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IEC 870-5-101

IEC 870-5-101

IEC 60870-5-101 communication protocol

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

Supported device types and versions

This protocol (known also as IEC 870-5-101 or IEC-101) supports:

  • standard IEC 60870-5-101:2003 in both "unbalanced" (master and slave) and "balanced" modes,

  • redundancy of communication lines according to the so-called Norwegian convention (Norwegian IEC 870-5-101 User Conventions).

Communication line configuration

Line categories:

Implementation is, according to the IEC870-5-101 standard, as follows:

  • The originator ASDU address is not present.

  • ASDU address is 1 byte, it is defined as the station address. ASDU addresses of all stations on one line must be different.

  • The cause of transmission is 1 byte (does not contain the Originator ASDU address).

  • The information object address is 2 bytes, it is defined as an I/O tag address.

If a redundant communication on two lines is required (Norwegian conventions) use the line categories Serial Line Redundant or SerialOverUDP Device Redundant.

If you require the system-redundant communication, use SerialOverUDP System&Line Redundant or Serial System&Line Redundant line categories. Providing that, this communication should be also network redundant, enter "Secondary line" for both "A System" and "B System". This configuration then works in such a way that it concurrently sends and receives data from two systems and each is network-redundantly connected in compliance with the so-called Norwegian convention (Norwegian IEC 870-5-101 User Conventions).

Communication station configuration

  • Communication protocol "IEC 870-5-101 balanced", "IEC 870-5-101 unbalanced primary (Master)" or "IEC 870-5-101 unbalanced secondary (Slave)".

  • The station address is a number in the range 0 - 255 and is used in the protocol as the ASDU address. It can be specified as a decimal number or as a hexadecimal number with a hash at the beginning (e.g. #0A).

  • The synchronization of the station real-time may be enabled also for the protocols "master" and "balanced - station A (controlling)". Set the synchronization period to a nonzero value. The synchronization is executed by ASDU 103 "Clock synchronization command" in the local time according to settings of the D2000 System.

The Browse button opens a browsing dialog for the station address. If the communication is functional, a dialog with the ASDU addresses received so far is displayed. The Refresh button can be used to clear the list of received ASDU addresses.

Note: in the case of the "slave" and "balanced" protocols, if an Interrogation (ASDU 100) or Counter Interrogation (ASDU 101) command arrives for the "broadcast" address (hexadecimal FF or FFFF according to the Link Address parameter), data from all stations will be sent.

Line protocol parameters

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

Table 1

Parameter

Meaning

Unit

Default value

Link Address

Common link address.

-

1

Length of ASDU Address

Length of ASDU address.

1/2 byte(s)

1

Length of Link Address

Length of common link address.

1/2 byte(s)

1

Length of Info Object Address

Length of info object address.

1/2/3 byte(s)

2

Length of Cause Of Transmission

Length of "Cause Of Transmission".

1/2 byte(s)

1

 

Retry Count

The delay between request retry in case of a communication failure.

-

2

Retry Timeout

The delay between retry of call in case of a communication error.

ms

100 millisecond

Wait First Timeout

Delay after sending the request before reading the response.

ms

100 millisecond

Wait Timeout

Delay between response readings until it is completed.

ms

500 millisecond

Max. Wait Retry

Retry count of response reading until it is completed.

-

6

No Data Timeout

Delay of next call "Request user data class 1/2" if no data have been received (only master).

ms

300 millisecond

Inactivity Timeout

Interval of connection monitoring. If no valid data have not been received, station status will go to a communication error. Switching of redundant devices in case of SerialOverUDP Device Redundant line (only slave).

ms

5 sec.

Moxa Timeout

The switching interval of the redundant devices MOXA NPort in case of communication error (only master, balanced).

sec.

10

Source Flags

Set flags FI..FL according to the source of line. If SerialOverUDP System+Line Redundant is used, the values will have these flags:

  • System A, primary line: FI

  • System A, secondary line: FJ

  • System B, primary line: FK

  • System B, secondary line: FL


Note: Flag was used in communication with redundant systems to distinguish the wrong values that were sent by a partner system, which was supposed to be passive and not to send nothing.

-

NO

No Output Flags

Activation of parameter results in ignoring flags FA..FH for output I/O tags. If this parameter is turned off, flags FA..FH are mapped to individual bits of a quality byte.

-

NO

Link Test Timeout

Interval of request sending "Test function for link" if timeout elapsed and no data telegrams were transferred (balanced only).

sec.

10

Single Value In Spontaneous Answer

When sending spontaneous changes, these will be sent one-per-ASDU and they will not be cumulated into longer packets. The parameter was implemented to handle a bug in a particular TM1703mic.

-

NO

Data Class

The class used for sending data (slave only). IEC 101 Master sends Class1 (high priority) and Class2 (normal) read data requests. Slave responds to them with data or a message that it has no data. In both Class1 and Class2 responses there is an ACD flag that the slave has Class1 data available. If set, the IEC 101 Master will then request Class1 data.

The parameter affects behavior as follows:

  • Class1&2 - IEC 101 Slave responds to Class1 and Class2 requests with data. The ACD flag sets if it has additional data.

  • Class1 - IEC 101 Slave sends all data as Class1 and responds to the Class2 requests that it has no data. The ACD flag sets if it has additional data.

  • Class2 - IEC 101 Slave sends all data as Class2 and responds to the Class1 requests that it has no data. The ACD flag sets to 0 (it does not have Class1 data).

  • Prio reply - IEC 101 Slave sends responses to command ASDUs as Class1 data and other ASDUs (value changes, responses to Interrogation) as Class2.
    Note: The responses to Interrogation (ASDU 100) and Counter Interrogation (ASDU 101) commands and all the values sent as a part of the response are also sent as Class1 data.

The default value of the parameter is Class1.

-

Class1&2
Class1
Class2
Prio reply

Single Request

Discard received data before sending a response (only slave). If a correct request is received and the IEC 101 Slave wants to send a response, it will clear the incoming queue before sending, if the queue has data in it. This parameter serves as a protection against various data duplications due to communication partner errors (e.g. OSI Monarch with RtuPing running during switching of active communication line).

-

NO

Filter Spontaneous Values

Filtering multiple spontaneous values of the same I/O tag when sending (only slave, balanced). If some I/O tags change so fast that there would be multiple values of the same I/O tag in one response to a data request, activating this parameter causes only one (latest) spontaneous value to be sent. See also the description of the Filter Minimum parameter.
Note: the filter does not affect the sending of commands (ASDU 45 and above).

 

NO

Filter Minimum

The number of requests in the output queue at which value filtering is activated, if enabled by the Filter Spontaneous Values ​​parameter. This parameter allows value filtering to be activated only in error conditions (e.g. excessive value generation in the D2000 CALC process) and not during normal operation.

-

0

 

Send Confirmation Command

Type of sent confirmation to write value (only slave, balanced).

-
7(CONF)
10(TERM)
7(CONF) and 10(TERM)

7(CONF)

Accept Confirmation Command

Type of record confirmation to be accepted successfully (only master, balanced).

-
7(CONF)
10(TERM)
7(CONF) or 10(TERM)

7(CONF) or 10(TERM)

Max. MTU

Limitation of data packet size (only slave, balanced).

bytes

220

Phys. Trans. Direction

Setting a bit DIR in balance mode (only balanced).

Station A(Controlling)
Station B(Controlled)

Station A(Controlling)

Single Byte Ack

Send single-byte ACK preferentially (0xE5).

YES/NO

NO

Interrog. Covers Counters

Send the call 100 and counter values on general interrogation (only slave, balanced).

YES/NO

YES

Send EOI

Send "end of interrogation command" to all ASDU (only slave).

YES/NO

YES

End of Initialization

If the value of the parameter is "1 - IC/CIC after EOI", then after receiving ASDU 70 (End of initialisation) the Interrogation Command will be sent again. The default value "0 - no IC/CIC after EOI" will cause ASDU 70 to be ignored.
Note: this parameter was implemented for SAT RTUs.

-

0

Send Interrog. in Sec. Direct.

Send general interrogation command in case of slave or balanced controlled station B (only slave, balanced).

YES/NO

NO

Sinaut Mode

Communication for the Sinaut Spectrum system, which requires non-standard behavior on redundant lines (different from the Norwegian convention).

YES/NO

NO

System Redundancy: Manages A Status Address

Address of station and output I/O tag with the status of system redundancy. The format of the address is Station Address, I/O tag address, for example. "1,1003".
The parameter is useful for SerialOverUDP System&Line Redundant lines, which enable communication with two independent control systems (e.g. main dispatching SED in Žilina and backup dispatching SED in Bratislava).
The parameter enables one to ignore values that are received from the control system, which is inactive just now, providing that the application knows which one is active or inactive. It can know it e.g. based on the value of the input I/O tag with the defined value.
This feature (information about active control system) will work provided that the station with the output I/O tag of Dout type exists with the same addresses as is defined in this parameter and the application must write True into it if "System A" is active, or False if "System B" (configured on the system redundant line) is active.

-

 

 

Ignore Unknown Addresses

If Ignore Unknown Addresses=TRUE, the D2000 KOM process will not show an error on its console or write it into log files in case the incoming value has the address not matching any of the addresses of I/O tags defined in the D2000 system.

-

False

Full Debug

A high level of communication tracking, the received values of I/O tags, and other debug information is shown.

YES/NO

NO

I/O tag configuration

Possible value types of I/O tags: Ai, Ao, Di, Dout, Ci, Co, Qi

I/O tag address is a numerical address of data object IOA (in the range 0 - 65535).  It can be specified as a decimal number or as a hexadecimal number with a hash at the beginning (e.g. #0A).
The I/O tag with an address starting with %IGNORE will be ignored.

In the case of command direction in master or balanced mode, it is necessary to configure a proper ASDU type:

ASDU type

I/O Tag type

45 - Single command

Dout

46 - Double command

Dout, Co

47 - Regulating step command

Dout

48 - Set point command, normalised value

Ao

49 - Set point command, scaled value

Co

50 - Set point command, short floating point value

Ao

51 - Bitstring of 32 bit

Co

58 - Single command with time tag CP56Time2a

Dout

59 - Double command with time tag CP56Time2a

Dout, Co

60 - Regulating step command with time tag CP56Time2a

Dout

61 - Set point command, normalised value with time tag CP56Time2a

Ao

62 - Set point command, scaled value with time tag CP56Time2a

Co

63 - Set point command, short floating point value with time tag CP56Time2a 

Ao

64 - Bitstring of 32 bit with time tag CP56Time2a

Co

In case of slave or balanced mode je is necessary to configure je proper ASDU type in v data direction:

ASDU type

I/O Tag type

1 - Single-point information

Di, Qi (On/Off), Ai, Ci

2 - Single-point information with time tag

Di, Qi (On/Off), Ai, Ci

3 - Double-point information

Qi, Ai, Ci

4 - Double-point information with time tag

Qi, Ai, Ci

5 - Step position information

Ci, Ai *

6 - Step position information with time tag

Ci, Ai *

7 - Bitstring of 32 bits

Ci, Ai

8 - Bitstring of 32 bits with time tag

Ci, Ai

9 - Measured value, normalized value

Ai

10 - Measured value, normalized value with time tag

Ai