EPOS4 / IDX: Important steps during initial commissioning

Topic:

What steps should be taken when commissioning an IDX or EPOS4 for the first time (or in case the motor or controller gets replaced)?

Solution:

It is mandatory that system and motor configuration of an IDX motor with integrated controller (i.e. "IDX ... IO", "IDX ... CO", "IDX ... ET" product types), or "EPOS4" is processed by maxon's "EPOS Studio" software.

The required "EPOS Setup" installation package (2GB) is available for free and can be downloaded with the button "Download EPOS Setup" at the bottom of the website http://epos.maxongroup.com.

There are two main important wizards present in the "EPOS Studio" which both have to be processed successively during initial commissioning:

"Startup" Wizard
The "Startup" wizard must be used to configure the basic data of the drive system and limiting application factors step by step.
"Regulation Tuning" Wizard
"Regulation Tuning" has to be processed as the successive wizard before controlled motor operation is possible.

There are also training videos available about EPOS4's initial commissioning by the two wizards:

Additional note: EC-frameless + TSX-MAG

For EC-frameless "DT" motors with "TSX MAG" encoder, it is mandatory to ensure that the rotor and stator matches to each other. These components are matched (= "paired") during production and got unique IDs. These IDs and consecutive numbers, which are printed on the rotor and stator must be identical. Otherwise "Regulation tuning" and motor operation will not work properly.
Please find more details in this linked Support Center document:
-> EC-frameless "DT" + "TSX-MAG": Malfunction due to mismatching pairing!

1.) Startup wizard

The drive system characteristics (= motor, gear, encoder) and the application limiting factors (e.g. maximum speeds and accelerations) must be properly configured step by step in the "Startup" wizard before "Regulation Tuning" or motor operation is possible.

Observe the correct (i.e. adapted to your system) configuration of all parameters even if these are not explicitly mentioned below. The following information lists only some of the most important parameters. Observe that all other parameters in the "Startup" wizard match your system components and application's requirements as well.

Motor configuration:

It is important that "Motor type", "Nominal current" and "Thermal time constant of the winding" are configured correctly according to the motor data sheet. These parameters are mandatory for motor winding overload protection by the so-called I2t limitation. Please refer to the following two Support Center documents to learn more details about I2t limitation:

Set the "Number of pole pairs" (of an EC motor) correctly as well. You find it also on the motor data sheet.

The motor data sheet also specifies a "Max. speed". However, this value is related to mechanical motor limits from bearings and winding. Depending on the supply voltage, the specified "Max. speed" (on the motor data sheet) can often not be reached, and it might not even be relevant in the application. Please configure the "Max speed" as required by the specific application and as can effectively be achieved with the supply voltage. Please find some more information about "Max speed" configuration in these Support Center documents:

Special case: IDX
The parameters "Motor type", "Thermal time constant winding", and "Number of pole pairs" are preconfigured in the IDX with integrated controller and cannot be modified. All other parameters are preconfigured and might need adjusting (e.g. "Max speed", "Following error window, "Max acceleration", ...).

Encoder configuration:

Please check and ensure that the encoder(s) in use are properly selected and the encoders resolution is configured properly.

In case of an incremental encoder please take care that its "Type" and "Number of pulses" are configured correctly. All required information is specified on the encoder data sheet:

In case of an SSI absolute encoder check and configure its parameters according to the data sheet. Take special care of the proper configuration of leading, multi-turn, single-turn, and trailing bit numbers.

Please find some hints about SSI configuration in this Support Center document:

EPOS4: SSI configuration features

Special case: IDX
The parameters of the encoder in the IDX with integrated controller are preconfigured and cannot be modified.

Limits:

Configure the parameters "Max acceleration" and "Following error window" in Startup wizards subtree "Limits" with reasonable values.

"Max acceleration" should be set in a way, so that the drive train (depending on the motor data, maximum motor current, mechanical limitations, and the load, etc.) can actually follow the configured acceleration and there is no risk of damaging or overloading mechanical components (e.g. because of too high torque at a gear's input or successive mechanics).

If a PLC processes motion profiling (= "Trajectory generation") and commands the EPOS4 or IDX by so-called "CSP - Cyclic Synchronous Position" or "CSV - Cyclic Synchronous Velocity" mode, "Max acceleration" is typically set to the maximum value (= 4294967295 rpm/s). It is assumed that the PLC or its motion control library and application code only uses acceptable acceleration and deceleration ramps for motion profiling and commanding the EPOS4 and IDX accordingly. The responsibility for commanding realistic acceleration values is part of the PLC's configuration and application code.
If the EPOS4 or IDX is operated in "PPM - Profile Position Mode" or "PVM - Profile Velocity Mode" (i.e. calculates motion profile on its own), "Max acceleration" values are typically configured in the range of some 10000 rpm/s up to some 100000 rpm/s.

The "Following error window" must be adjusted based on the motor shaft encoder's resolution. The following rule of thumb can be used:

"Following error window" = 1 ... 4 times of encoder increments per motor shaft turn
i.e.
- Incremental encoder:
  "Following error window" = 4 ... 16 x encoder's specified cpt. value
  (cpt. = counts per turn)
  e.g. Encoder with 500 cpt.
  => "Following error window" = 2000 ... 8000 inc.
- Absolute encoder:
  "Following error window" = 1 ... 4 x 2^n
  n = absolute encoder's configured "Single-turn position" number of bits
  e.g. Encoder with 14 bit "Single-turn position"
  => "Following error window" = 16384 ... 65536 inc.

Special case: IDX

IDX's "Following error window" is often preconfigured too low by default, especially if there is a high resolution encoder (like EMT absolute encoder) mounted internally. Please configure the "Following error window" of the IDX according to the internal encoder type and its resolution (e.g. in case of an EMT: "Following error window" = 16384 inc. at least).

General note:
If the "Following error window" is configured too low and the commanded acceleration is very high, a "Following error" (0x8611) can occur as soon as the motor starts to move.

2.) Regulation Tuning

After all configuration steps had been processed by the "Startup" wizard and finally saved by pressing the "Finish" button, the "Regulation" tuning has to be processed.

Current control tuning:

Current control is the subordinated control loop of all other control loops, i.e. "Current control" is always active independent of what operating mode will be in use later on.

Important:

It is mandatory that "Current control" tuning is processed first (i.e. optimized current control parameters have to be present) before the tuning of other control loops can be processed.

Hint:

The load on the motor or whether the motor shaft can move or not has no impact on the "Current control" parameters. A blocked motor shaft often results in the best tuning results.

After successfully tuning of "Current control" parameters, press the "Next" button to go on with "Velocity" and "Position" control loop's parameter tuning.

Special case: IDX
The "Current control" parameters of the IDX with integrated controller are predefined. There is usually no need to adapt IDX's "Current control" parameters. The "Current control" tuning is not even offered in the IDX "Regulation Tuning" wizard, i.e. you can start directly with "Velocity" and "Position control" tuning.

Velocity and Position control tuning:

Important:

The motor's output shaft has to be able to move freely (i.e. without any limitation) during velocity and position tuning!
- Do not block the motor shaft!
  Ensure that the mechanics does not limit the motion, or a limit switch is hit during the oscillating motion. Ensure that there is no risk of a collision with other mechanical elements.
- Ensure that there is no risk of injuring humans by the oscillating motor shaft or mounted mechanics present.
  There must be some emergency button present to cut off the supply voltage in the event of danger.
Optimal velocity and position control parameters are influenced by the load mounted on the motor shaft.
- Ideally, the velocity and position control tuning should be processed with the same load as present during motor operation later on, esp. if it is direct drive (i.e. without a gear).
- If tuning with mounted mechanics or load is not possible in a drive system (e.g. due to movement limitations), good controller parameters can often be determined even without load; in particular for motor combinations with a 2- or multi-stage gear.

Cross reference:

EC-frameless "DT" + "TSX-MAG": Malfunction due to mismatching pairing!

Support Center

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