Siemens SIPROTEC 5 Handbuch Seite 188

IEC 60870-5-104
4.3 Interoperabilität
Link Transmission Procedure
When using an unbalanced link layer, the following ASDU types are returned in class 2 messages (low priority)
with the indicated causes of transmission:
The standard assignment of ASDUs to class 2 messages is used as follows:
Type Identification
9, 11, 13, 21
A special assignment of ASDUs to class 2 messages is used as follows:
Type Identification
N.A.
Note: (In response to a class 2 poll, a controlled station may respond with class 1 data when there is no class 2
data available).
Application Layer
4.3.6
Transmission Mode for Application Data
Mode 1 (Least significant octet first), as defined in clause 4.10 of IEC 60870-5-4, is used exclusively in this
companion standard.
Common Address of ASDU
(System-specific parameter, all configurations that are used are to be marked X)
1 octect (not supported)
Information Object Address
(System-specific parameter, all configurations that are used are to be marked X)
1 octet (not supported)
Structured
3 octets
Cause of Transmission
(System-specific parameter, all configurations that are used are to be marked X)
1 octet (not supported)
Length of APDU
(System-specific parameter, specify the maximum length of the APDU per system)
The maximum length of APDU for both directions is 253. It is a fixed system parameter
Maximum length of APDU per system in control direction (not supported)
Maximum length of APDU per system in monitor direction (not supported)
188
Address Field of the Link
Structured
Unstructured
Cause of Transmission
<1>
Cause of Transmission
N.A.
2 octets
2 octets (not supported)
Unstructured
2 octets (with originator address) Originator address is set
to 0 if not used
Frame Length
SIPROTEC 5, Communication Protocols, Handbuch
C53000-L1800-C055-H, Ausgabe 07.2023