- How to read the motor's current draw by an EPOS or IDX?
The motor current is NOT(!) identical with the current reported by the power supply of the motor controller. The current display of the power supply or measurements with a multimeter are therefore misleading with regard to the motor current.
The motor control is a so-called power converter, i.e. the current and voltage at the motor varies permanently and only the power output from the power supply (= current x voltage) and the power output to the motor correspond (if losses are neglected). More detailed information on this topic can be found in the following linked Support Center document:
EPOS Studio's "Data Recorder":
You can easily record the motor current by EPOS Studio's "Data recorder".
Select "Current actual value averaged" by one of the recorder's channels:
If you want to share any recordings with maxon's support team, please right-click in the stopped graphics and select "Save Recorded Data". Attach the resulting *.csv file to your support request then. Do not(!) just provide a screenshot. Screenshots are not sufficient for any in-depth analysis.
Reading motor current by a master controller:
If you want to read out the motor current from your master application (e.g. on a PLC, PC, Raspberry Pi, microcontroller), the object "Current actual value averaged" (0x30D1/01) must be accessed.
When using the "EPOS Command Library" (by a PC or Raspberry Pi application code) the function call "VCS_GetCurrentIsAveragedEx" can be used to read out the motor current.
Always record or read the "Current actual value averaged" (0x30D1/01) which is a filtered value. The "Current actual value" (0x30D1/02) has a lot of noise due to current measurement principle.
- Motor controllers: Input current versus Motor current, Power Conversion
- Motor current measurement in case of a PWM power amplifier
- What is the power consumption of a controller?
- EPOS4 / IDX: Calculation of the electrical motor power
- ESCON: Checking the motor current draw