IEC 870-5-104 Server
IEC 60870-5-104 Server communication protocol
Supported device types and versions
Communication line configuration
Communication station configuration
I/O tag configuration
TELL commands
Literature
Document revisions
Supported device types and versions
This protocol implements a server-side of IEC-104 communication (known also as IEC 870-5-104 or IEC-104).
Communication supports reading and writing data by means of the IEC 60870-5-104 communication protocol operating on the basis of TCP network communication. D2000 system works in the IEC 60870-5-104 server mode (slave). It is able to communicate with multiple (N) clients (masters). Implementation is according to the IEC 60870-5-104 standard as follows:
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 a line, a different ASDU address must be defined.
Cause of transmission is 2 bytes (it also contains Originator ASDU address)
Information object address IS 3 bytes, it is defined as an I/O tag address.
The following ASDU types in the direction of monitoring are implemented (from the D2000 system to the control station and also vice-versa in balanced mode):
Table 1
ASDU type | I/O tag type |
|---|---|
1 - Single-point information | Dout |
2 - Single-point information with time tag | Dout |
3 - Double-point information | Dout,Cout |
4 - Double-point information with time tag | Dout,Cout |
5 - Step position information | Cout |
6 - Step position information with time tag | Cout |
7 - Bitstring of 32 bits | Cout |
8 - Bitstring of 32 bits with time tag | Cout |
9 - Measured value, normalized value | Ao |
10 - Measured value, normalized value with time tag | Ao |
11 - Measured value, scaled value | Cout |
12 - Measured value, scaled value with time tag | Cout |
13 - Measured value, short floating point value | Aout |
14 - Measured value, short floating point value with time tag | Aout |
15 - Integrated totals | Cout |
16 - Integrated totals with time tag | Cout |
20 - Packed single-point information with status change detection | Cout * |
21 - Measured value, normalized value without quality descriptor | Ai |
30 - Single-point information with time tag CP56Time2a | Dout |
31 - Double-point information with CP56Time2a tag | Dout,Cout |
32 - Step position information with CP56Time2a tag | Cout |
33 - Bitstring of 32 bits with CP56Time2a tag | Cout |
34 - Measured value, normalized value with CP56Time2a tag | Aout |
35 - Measured value, scaled value with CP56Time2a tag | Cout |
36 - Measured value, short floating point value with time tag CP56Time2a | Aout |
37 - Integrated totals with time tag CP56Time2a | Cout |
241 - 64-bit floating point value (Ipesoft & URAP implementation) | Ao |
243 - 64-bit floating point value with time tag CP56Time2a (Ipesoft & URAP implementation) | Ao |
251 - Archive data values (Ipesoft's implementation) | none ** |
252 - D2000 Unival (Ipesoft's implementation) | all |
Note: For setting individual bits of the quality byte (SIQ for ASDU 1,2,30; DIQ for ASDU 3,4,31; QDS for ASDU 5..14,20,32..36), the flags A (0.bit), B (1.bit) .. H (7.bit) are used.
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
The exception is the bits, which are set directly by a value (e.g. for ASDU 1, the 0.bit is not set by the A flag but by the value of output I/O tag).
If the Invalid attribute is set for a new value, the highest bit (IV) will be set in the status byte for all ASDUs (except for ASDU 21, which does not have a status byte).
* - Status is taken as low 2 bytes, Status change detection is taken as highest 2 bytes of a 32-bit integer.
The following ASDU types in the direction of control are implemented (from the control station to D2000, also the opposite direction in balanced mode):
Table 2
ASDU type | I/O tag type |
|---|---|
45 - Single command | Di, Qi |
46 - Double command | Qi |
47 - Regulating step command | Di, Qi |
48 - Set point command, normalised value | Ai |
49 - Set point command, scaled value | Ci |
50 - Set point command, short floating point value | Ai |
51 - Bitstring of 32 bit | Ci |
58 - Single command with time tag CP56Time2a | Di, Qi |
59 - Double command with time tag CP56Time2a | Qi |
60 - Regulating step command with time tag CP56Time2a | Di, Qi |
61 - Set point command, normalised value with time tag CP56Time2a | Ai |
62 - Set point command, scaled value with time tag CP56Time2a | Ci |
63 - Set point command, short floating point value with time tag CP56Time2a | Ai |
64 - Bitstring of 32 bit with time tag CP56Time2a | Ci |
250 - Archive data request command (Ipesoft's implementation) | none ** |
252 - D2000 Unival (Ipesoft's implementation) | all (except Qi) |
Bits of "status" byte (SCO fro ASDU 45,58; DCO for ASDU 46,59; RCO for ASDU 47,60; QOS for ASDU 48..50,61..63) causes setting the A (0.bit), B (1.bit) .. H (7.bit) flags with an exception for the bits which are directly set by the value of a variable (SCO bit 0, DCO and RCS bits 0-1). After receiving a response (positive/negative), the A .. H flags are set according to the bits of the "status" byte.
When writing values, the value of 6 [Activation] is expected as CauseOfTransmission. The response of the controlled station depends on the setting of the CMDC parameter. Originator ASDU address will be used the same as is in the received command.
Establishing a connection:
D2000 KOM process is waiting on a TCP port and, after establishing a connection, is waiting for receiving the StartDT Act U-frame from the client. Then it sends StartDT Con as a response (it is possible to send TestFrame before StartDT Act).
If the EOI parameter is set, the D2000 KOM process will send ASDU 70 [End of initialization], the initial OA address (configured as a line number) is used as Originator ASDU address.
If the Synchronisation period parameter (the Time parameters tab) for some of the stations is different from 0, ASDU 103 [Clock synchronisation command] with CauseOfTransmission= 6 [Activation] will be sent in the configured period. The initial OA address (configured as a line number) resp. Originator ASDU of the last received ASDU 100 or 101 will be used as Originator ASDU address.
D2000 KOM process sends new values acquired from the D2000 Server process for variables with ASDU 1..14, 20, 21, 30 .. 36 to a client, which sent ASDU 100 [Interrogation Command] and new values for variables with ASDU 15,16,37 to a client, which sent ASDU 101 [Counter Interrogation Command]
D2000 KOM process accepts time synchronisation using ASDU 103 [Clock synchronisation command] with CauseOfTransmission=6 [Activation] or 3 [Spontaneous]. If CauseOfTransmission= 6, its response dependd on setting of the CMDC parameter. If CauseOfTransmission= 3, it does not respond.
D2000 KOM process responds to received commands (ASDU 45..51, 58..64) with CauseOfTransmission= 6 [Activation] dependd on setting of the CMDC parameter.
Originator ASDU address (OA): initial OA is set as TCP line number in the configuration. The address will be used for the optional sending of the ASDU 70 [End of initialization] at the beginning of a connection and always for sending new values.
After receiving ASDU 100 or 101, the current values of all output I/O tags are sent (which don't have an Invalid attribute set) with the same OA as contained in ASDU 100 or 101.
As responses to received commands (ASDU 45..51, 58..64), the confirmations using the same ASDUs as received command are sent.
The D2000 system also supports a balanced mode. In this mode, the task of controlled and control stations is symmetrical. In this mode, the D2000 system sends commands and ASDUs 100/101. The balanced mode may be used only if it is supported by the partner station. An advantage is that the D2000 system can send ASDU 100 [Interrogation Command] a 101 [Counter Interrogation Command] and receives the current values of input I/O tags (configured as ASDU 1-40) after the connection was disconnected and re-established. It is suitable to configure single-shot commands as ASDUs 45 - 64; they are not repeated after re-establishing the connection.
Writing of an output I/O tag:
When writing IEC 104 values (ASDUs 1-40), the rules of server protocols apply.
When writing IEC 104 commands (ASDUs 45-64) in the balanced mode, ASDU is considered to be confirmed (the Transient flag is cleared) in dependence on the CMDC parameter. If the connection to a client is lost when writing, the writing success depends on the PW parameter.
Communication line configuration
Communication line category: TCP/IP-TCP
TCP Parameters
Required to define the server parameters
Host: string containing at most 80 characters – the name of the network interface in form of INET (name or numerical address a.b.c.d, e.g. 192.168.0.1) used for receiving clients by the D2000 KOM process. If the name is ALL or *, the D2000 KOM process will listen on all network interfaces of the computer, where is running.
Port: TCP port number (0..65535), where the D2000 KOM process is listening.
Line number: will be used as Originator ASDU address (1 byte, 0-255).
Note: Starting from D2000 version 7.02.004 the flags A to P of the value of the communication line are used for informing about connected active clients. An active client is a client who after establishing the connection sent U-frame StartDT Act, i.e. asked for sending the data. The first connected active client will cause a change of flag A to TRUE, the second flag B, etc up to flag P and continuing again with the first flag A. If the client sends the StopDT Act U-frame (requesting the server to stop sending data) or disconnects, the value of its flag will be changed to FALSE.
Communication station configuration
Communication protocol: IEC870-TCP Server.
The station address is a number within the range 0...65535, it defines 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).
Note 2: The protocol supports sending long time stamps (CP56Time2a tag) in local time or UTC time with defined offset (see the Use monotonic UTC time+ parameter).
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.
Station protocol parameters
The following parameters can be defined as station protocol parameters:
Table 3
Keyword | Full name | Meaning | Unit | Default value |
|---|---|---|---|---|
CMDC | Command Confirm | Confirmation of control ASDU. | - | 1 |
The parameters are intended for the configuration of a communication station for communication between two D2000 systems using ASDU 252 - D2000 Unival (Ipesoft's implementation). more ... | ||||
D2H64 | D2000 64-bit Historical Values | When sending historical values (as an answer to a request for historical data), ASDU 249 will be used, which uses a 64-bit representation of floating points (the same as D2000 internally), instead of default ASDU 251 (which encodes the values as 32-bit floating points) to improve precision. | - | False |
DBGI | Debug Input | A mask for debug levels of input data. The meaning of bits is as follows:
| - | 0 |
DBGO | Debug Output | A mask for debug levels of output data. The meaning of bits is as follows:
| - | 0 |
EOI | End of initialization | If EOI=0, the D2000 KOM process doesn't send ASDU 70 (End of initialisation). If EOI=1 and a client sends StartDT U-frame Act, the D2000 KOM process responds by StartDT Con and sends ASDU 70. | - | 0 |
GISN | GI Send New | If GISN=True, then the D2000 KOM process after receiving the General Interrogation command sends also values with newer times than is the time when the command is received. The value of the GI Send New parameter must be True to send values with future times in a reply to the General Interrogation command. | - | False |
ICF3 | Ignore Control Field 3 bit 0 | Determines behavior if ASDU contains Control Field with bit 0 (test) set in the 3rd byte (Receive).
The feature is useful when creating a redundant TCP connection (TCP Redundant line + IEC 870-5-104 protocol). That active client should send ASDUs without the Test bit set and the passive client should send ASDUs with the Test bit set. | - | False |
III | Ignore Invalids on Interrogation | If this parameter is set on a station, the D2000 KOM process will not send values of I/O tags which are Invalid or Unknown, in a reply for ASDU 100 and 101 (Interrogation/Counter interrogation commands). The parameter can be used e.g. for control applications - if sending Invalid values causes problems in control. | - | False |
IITF | Ignore Invalid Time Flag | Determines behavior if the ASDU has the Invalid (IV) flag set within the timestamp:
| - | False |
IT | Ignore Tests | Determines behavior if ASDU contains the highest 7th bit (Test) set in CauseOfTransmission.
The feature is useful when creating a redundant TCP connection. The active client should send ASDUs without the Test bit set and the passive client should send ASDUs with the Test bit set. | - | 0 |
IUA | Ignore Unknown Addresses | If IUA=TRUE, the D2000 KOM process will not show an error on its console or write it into log files in case that incoming value has the address not matching any of the addresses of I/O tags defined in the D2000 system. | - | False |
II | Implicit Interrogation | Balanced mode: After connecting the client, the values of all variables are automatically sent without any need for ASDU 100 and 101 [Interrogation/Counter Interrogation Command] requests. | - | False |
ICCI | Interrogation Covers Counter Interrogation | As a reply to Interrogation, ASDUs 15,16,37 (Integrated Totals) will be also sent, which are by default requested by ASDU 101 [Counter Interrogation]. | - | False |
IGO | Interrogation Groups Objects | Optimization of sending values during General Interrogation (answer to Interrogation Command/Counter Interrogation Command). If IGO=True, multiple values will be sent inside a single ASDU (so that the length of ASDU is within maximum defined by the standard - 253 Bytes). This parameter does not influence change-based sending of values during normal communication. | - | False |
IWOT | Interrogation WithOut Timestamps | If Interrogation WithOut Timestamp=True then values sent as a response to ASDU 100 [Interrogation Command] will be sent as ASDUs without timestamps. | - | False |
K | K | Sending window size i.e. packet quantity, which is sent by the D2000 KOM process without receiving a confirmation (S-frame or I-frame). According to the standard, the default value is 12. | - | 12 |
MC | Maximum Clients | The maximum number of connected clients. The parameter is needed for D2000 OpenVMS, where a task pool containing 2 * MC tasks for client handling (one task for receiving data, one task for sending data) is created during KOM startup. If the value of the Maximum Clients parameter is equal to 0, the number of clients is not limited and threads are created dynamically as needed. | ||