Conversion Factors (Factor Group) - Festo CiA 402 Manual

4 Setting parameters
Signature MSB
ASCII
hex
Tab. 4.2 Example for ASCII text "save"
If the default parameter set should also be taken over into the application parameter set, then the
object 1010 _01 (save_all_parameters) must be written with the ASCII text "save".
h h
If the object is written via an SDO, the default behaviour is that the SDO is only answered after saving.
4.2

Conversion factors (Factor Group)

Overview
Motor controllers are used in a number of applications: As direct drive, with following gear, for linear
drive, etc. To permit easy parametrisation, the motor controller can be parametrised with the help of
the factor group so that the user can specify or read out all variables, such as speed, directly in the
desired units at the output (e.g. with a linear axis position value in millimetres and speeds in milli-
metres per second). The motor controller then uses the factor group to calculate the entries in its in-
ternal units of measurement. For each physical variable, (position, speed and acceleration), there is a
conversion factor available to adapt the user units to the own application. The units set through the
factor group are generally designated position_units, speed_units or acceleration_units. The following
sketch illustrates the function of the factor group:
User units
Position units
Speed units
Acceleration units
Fig. 4.2 Factor group
All parameters are stored in the motor controller in its internal units and only converted with the help of
the factor group when being written in or read out.
Recommendation: Set the factor group first during parameterisation and do not change it during the
parameterisation process.
Festo – GDCP-CMMS/D-C-CO-EN – 1404NH – English
e v
65 76
h
Factor group
Position
Position Factor
Speed
Velocity factor
Acceleration
Acceleration factor
a
61
h h
±1
±1
position_polarity_flag
±1
±1
velocity_polarity_flag
LSB
s
73
h
Internal controller
units
Increments (Inc.)
1 Rotation
min
1 Rotation min
256 sec
49