Siemens SINUMERIK 840Di Diagnostic Manual page 412

Overview of Alarms
NCK alarms
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).
Reaction: Mode group not ready.
The NC switches to follow-up mode.
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.
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 therefore 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 Clear alarm with the RESET key in all channels of this mode group. Restart part program.
Continuation:
25021 Axis %1 zero mark monitoring of passive encoder
Parameters: %1 = Axis name, spindle number
Definitions: Monitoring relates to the encoder that is not used by the position control! (Interface signal DB 31 - 48,
DBX 1.5 = 0 or 1.6 = 0)
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!
Reaction: Alarm display.
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 therefore 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 ENC_ZERO_MON_ACTIVE [n]=... N ...
encoder number: 1, 2) to 0.
Program Clear alarm with the Delete key or NC START.
Continuation:
2-412
© Siemens AG, 2006. All rights reserved
SINUMERIK, SIMODRIVE Diagnostics Manual (DA), 11/2006 Edition
11/2006