Data library
8.2 Scaling
3WL/3VL circuit breakers with communication capability - PROFIBUS
176
System Manual, 03/2011, A5E01051353-02
8.2
Scaling
The measured values are always transferred as integer values (format "INTEGER" = "INT")
and never as Floating Point numbers (format "REAL"). These values can be signed. For this,
a scaling factor must be added in the case of some measured values so that the transferred
measured value can be correctly interpreted. The scaling factor to be displayed in each case
can be taken from the table shown below (from "data points").
Frequency example
The measured value of the current frequency (data point #262) varies between 15.00 and
440.00 Hz. The decimal places could not be communicated using the INTEGER format
without scaling. For this reason, the measured value is scaled with 10
2
, and a value of
between 1500 and 44000 is communicated. At the receiver end (PROFIBUS master), this
value must now be multiplied by the scaling factor corresponding to the exponent of 10 (-2,
multiplication by 10
-2
). The exponent at the receiver end is always specified for the scaling
factor.
8.3
Abbreviations of the data sources
Table 8- 1
The following abbreviations are used in the data sources:
Abbreviation
Meaning
ETU
Electronic trip unit
Meter. fct.
Metering function or metering function PLUS
DI
Digital input module
DO
Digital output module
BDA
Breaker Data Adapter PLUS
BSS
Breaker Status Sensor
conf. DO
Configurable digital output module