ABB RER620 - Application Layer

Section 3 1MAC302441-MB A
IEC 60870-5-101/104 protocol implementation
42 RER620
Point List Manual
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.
8.5 Application Layer
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”)
Information object address
(system-specific parameter, all configurations that are used are to be marked “X”)
Cause of transmission
(system-specific parameter, all configurations that are used are to be marked “X”)
A special assignment of ASDUs to class 2 messages is used as follows:
Type Identification Cause of Transmission
X
One octet
X
Two octets
X
One octet
X
Structured
X
Two octets
X
Unstructured
X
Three octets
X
One octet
X
Two octets (with originator address). Set to zero in case of no originator address.