1MRS750527-MUM
REF 54_
115
Feeder Terminal
Technical Reference Manual, General
9.4. Class 2 data
The measurement (analog) values are transported to the control system as a response
to a class 2 request command. The class 2 data is always cyclically updated
(COT=2). Refer to
Table 9.5.-3 on page 124 for measurement data.
Class 2 measurand sets (ASDU frames)
The IEC 60870-5-103 standard defines the measurands to be transmitted as either
Meas I (typeId 3) or Meas II (typeId 9) ASDU frames. According to the standard,
the Meas I ASDU can have four different profiles and Meas II has one profile. These
five profiles are supported in the REF 54_. In addition, there are twelve more private
class 2 ASDU frames defined. The user can choose which one of these twelve
measurand sets to use. The measurand set number (1...17) can be adjusted via the
“Frame type” parameter.
The measurand of the RTD card can be transmitted on its own frame. If the RTD
data frame parameter is set to one, every other class 2 data is an RTD data frame.
The alternate frame is RTD data frame and the another one is normal user selectable
data frame.
Class 2 value scaling
The IEC 60870-5-103 standard defines the scale (max range) of the measurements
to be either 1.2 or 2.4 times the rated value for the measurement. The selection
between the 1.2 scaling or the 2.4 scaling can be done via the “Scale factor”
parameter. In the REF 54_ menu, the values are 0 = 1.2 and 1 = 2.4.
In order for the analog (measurement) data to become available on the
IEC 60870-5-103 interface, the measurement applications must have a proper
threshold value selected for the measurement.
9.5. Default mappings
Explanations to Table 9.5.-1:
St
Status
A According to the IEC 60870-5-103 standard
B According to “Digitale Stationsleittechnik - Ergänzende Empfehlungen zur
Anwendung in Verteilnetzstationen”
P Private definition
Ftyp
Function type
Note: If stated as *), the signal type Ftyp corresponds with the unit function type.
Unit function type may be adjusted via the “Function type” parameter.
InfNum
Information element number
GI
General interrogation
0 = Not in interrogation
1 = Interrogable
Typ
TypeId
COT
Cause of transmission values
1 Spontaneous
9 Interrogated