ETEL DSC2P/DSC2V Servo Controller Debugging Guide

Phasing fault diagnosis during initialization

Brushless motors (including ETEL core and coreless linear motors) must undergo initialization (Phasing) upon initial power on to determine the initial electrical angle of the rotor relative to the stator poles. If initialization fails, the motor will not be able to output normally or experience "runaway".

3.1 K90=2 (constant current initialization) common problems

This is the most commonly used initialization method, suitable for most iron core and iron core less motors. During initialization, the controller injects a constant current into the motor winding to move the rotor (or rotor) to a stable equilibrium point, with a movement distance not exceeding one magnetic pole cycle (usually 32mm). The parameters K92 (constant current amplitude) and K94 (initialization time) are crucial.

Fault 1: During the initialization process, the motor does not move or moves very little, and then reports "Initialize LOW CUR" (M64=153) or "TIMEOUT AUT CMD" (M64=156).

Reasons and Countermeasures:

K92 is set too low, and the electromagnetic force is insufficient to overcome static friction. K92 can be gradually increased (but not exceeding the incremental value corresponding to the peak current of the motor).

The K94 time is too short, and the motor has not yet reached a stable equilibrium point. The typical value is 5000 (corresponding to 5 seconds), which can be increased to 10000~15000 for large inertia loads.

If the motor is equipped with a brake, it is necessary to confirm that the brake has been released (controlled through digital output).

Fault 2: During initialization, the motor moves too far (exceeding ± 20% of the magnetic pole period), and reports "Initialize HIGH CUR" (M64=154).

Reason and countermeasures: K92 is too high, causing the rotor to rush over multiple equilibrium points. The K92 value should be reduced or the "small displacement initialization" mode (K90=6) should be enabled.

3.2 Application of K90=6 (small displacement initialization)

For vertical axis or high friction systems, constant current initialization may cause the load to slide or impact the mechanical limit. Small displacement initialization measures the position of the motor through short-term pulse current measurement, with almost no visible movement. This mode depends on parameters K91 (pulse current amplitude) and K101 (pulse interval time).

Debugging tip: It is recommended to set K91 to around 5% of K60 (force/torque limit) initially, and gradually increase it if it reports "Initial LOW CUR"; If it reports' Initial LOW TIME '(M64=155), K101 should be increased to extend the pulse interval, especially for high inertia systems, giving the motor enough time to respond to pulse excitation.

3.3 Phase reversal (K56) and AUT command

If the output direction of the motor is opposite to the command after initialization, or if K53 (phase adjustment value) cannot converge, it is usually necessary to execute AUT.<axis>=10 (bit1+bit3) to automatically calculate K56 (phase sequence reversal) and K53 (fine phase adjustment). Section 12.8 of the manual states that the AUT command is only executed in the "Power Off" state, and during the execution process, the controller will briefly move the motor to find the optimal pointer position for the commutation meter.

Attention: For iron core less motors, the current loop gain K80 calculated by AUT may not be accurate (as explicitly stated in the manual). In this case, K80 and K81 (current loop proportional/integral gain) should be manually adjusted.

Homing mode selection and exception handling

Return to zero (IND command) is used to establish the origin of the mechanical coordinate system. The ETEL controller offers up to 40 zeroing modes (K40), including mechanical limit switches, origin switches, encoder reference pulses (Index), and their combinations.

4.1 Zero return timeout or collision limit

The most common error is "SING IDX SEARCH" (M64=62) or "MULT IDX SEARCH" (M64=61), indicating that the reference pulse was not found within the specified search range. At this point, it is necessary to check:

K41 (zeroing speed) and K42 (zeroing acceleration): If the speed is too fast, the encoder may miss the Index pulse. Suggest setting K41 to 10%~20% of the rated speed.

K43 (limit detection tracking error) and K44 (limit detection force limit): If the tracking error or torque exceeds the set value before the mechanical limit is triggered, the controller will mistakenly believe that the hard limit has been reached and stop the search. Ensure that K43>50% of K30 (tracking error limit) and K44<80% of K60 (force limit).

For multi reference pulse encoders (such as Heidenhain LIDA series), the parameter K75 (reference pulse spacing) must be precisely set, otherwise multi pulse decoding will fail.

4.2 Zeroing completed, but the accuracy of the original point repetition is poor

If the deviation of the origin position after each zeroing exceeds several incremental units, the possible reasons may be:

Return to zero direction setting error (K40's "positive"/"negative" does not match the encoder Index signal edge).