Sinumerik Alarm 25020 Axis %1 zero mark monitoring of active encoder

Sinumerik Alarm 25020 Axis %1 zero mark monitoring of active encoder

Parameters:
%1 = Axis name, spindle number

Definitions:
The position encoder pulses between 2 zero marker pulses are counted (hardware function). A check is made in the interpolation cycle grid (standard setting 4 ms) as to whether the encoder always issues the same number of pulses between the zero markers. As soon as a difference is registered in the 4 counter bits of lowest significance, an alarm is triggered! The alarm can be reprogrammed in the MD ALARM_REACTION_CHAN_NOREADY (channel not ready).

Reactions:
– The NC switches to follow-up mode.
– Mode group not ready.
– Channel not ready.
– NC Start disable in this channel.
– Axes of this channel must be re-referenced.
– Interface signals are set.
– Alarm display.
– NC Stop on alarm.
– Channel not ready.
– If the axis is a single axis when this alarm is triggered, the alarm is only effective for this axis (not effective for e.g. the channel or mode group)

Remedy:
Please inform the authorized personnel/service department. The differences can result from transmission errors, disturbances, encoder hardware faults or from the evaluation electronics in the encoder used for position control. The actual value branch must there- fore be checked: 1. Transmission path: Check the actual-value connector on the motor and on the FDD module for correct contacting, encoder cable for continuity, and also check for short-circuits or grounding (loose contact?). 2. Encoder pulses: Encoder power supply within the tolerance limits? 3. Evaluation electronics: Replace or reconfigure the drive module used. Monitoring can be switched off by setting machine data 36310 ENC_ZERO_MONITORING [n]=… N … encoder number: 1, 2) is set to 0.

Program Continuation:
Clear alarm with the RESET key in all channels of this mode group. Restart part program.