Advanced commissioning
7.6 Selecting physical units
SIMATIC ET 200pro FC-2 converter
114
Operating Instructions, 04/2018, FW V4.7 SP10, A5E34257324B AF
Options when selecting the system of units
The following options apply when selecting the system of units:
●
p0505 = 1: System of units SI (factory setting)
Torque [Nm], power [kW], temperature [°C or K]
●
p0505 = 2: Referred system of units/SI
Represented as [%]
●
p0505 = 3: US system of units
Torque [lbf ft], power [hp], temperature [°F]
●
p0505 = 4: System of units, referred/US
Represented as [%]
Special features
The values for p0505 = 2 and for p0505 = 4 - represented in the converter - are identical.
However, the reference to SI or US units is required for internal calculations and to output
physical variables.
For variables, which cannot be represented as [%], then the following applies:
p0505 = 1
≙
p0505 = 2 and p0505 = 3
≙
p0505 = 4.
In the case of variables whose units are identical in the SI system and US system, and which
can be displayed as a percentage, the following applies:
p0505 = 1
≙
p0505 = 3 and p0505 = 2
≙
p0505 = 4.
Reference variables
There is a reference variable in the converter for most parameters with physical units. When
the referred representation [%] is set, then the converter scales the physical variables based
on the particular reference variable.
When the reference variable changes, then the significance of the scaled value also
changes. Example:
●
Reference speed = 1500 rpm
→
fixed speed = 80 %
≙
1200 rpm
●
Reference speed = 3000 rpm
→
fixed speed = 80 %
≙
2400 rpm
For each parameter you can find the associated reference variable for scaling in the List
Manual. Example: r0065 is scaled with reference variable p2000.
If scaling is not specified in the List Manual, then the converter always represents/displays
the parameter unscaled (not normalized).
Groups of units
The parameters associated with the selection of a physical unit, belong to different groups of
units.
You can find the associated group of units in the List Manual for each parameter. Example:
r0333 belongs to unit group 7_4.
