Siemens SINUMERIK 840D sl Series Diagnostics Manual page 323

08/2005
Phase 2 of reference point approach ends when the zero marker of the encoder has been
detected after the rising/falling edge of the PLC interface signal "DECELERATION REF-
ERENCE POINT APPROACH" (DB 31 - 48, DBX 12.7) has given the trigger start. The
maximum distance between the trigger start and the zero marker that follows is defined in
the machine data 34060 REFP_MAX_MARKER_DIST.
The monitor prevents a zero marker signal from being overtraveled and the next being
evaluated as reference point signal. (Faulty cam adjustment or excessive delay by the
PLC user program).
Reactions: - NC Start disable in this channel.
- Interface signals are set.
- Alarm display.
- NC Stop on alarm.
Remedy: Please inform the authorized personnel/service department. Check the cam adjustment
and make sure that the distance is sufficient between the end of the cam and the zero
marker signal that follows. The path must be greater than the axis can cover in the PLC
cycle time.
Increase the machine data 34060 REFP_MAX_MARKER_DIST, but do not select a value
greater than the distance between the 2 zero markers. This might result in the monitor
being switched off.
Program Con- Clear alarm with the RESET key. Restart part program
tinuation:
20003
Channel %1 axis %2 measuring system error
Parameters: %1 = Channel number
%2 = Axis name, spindle number
Definitions: In a measuring system with distance-coded reference marks, the distance between two
adjacent markers has been found to be more than twice the distance entered in the
machine data 34300 ENC_REFP_MARKER_DIST.
The control issues the alarm after having made a second attempt in reverse direction with
half the traversing velocity and detecting that the distance is too large again.
Reactions: - NC Start disable in this channel.
- Interface signals are set.
- Alarm display.
- NC Stop on alarm.
Remedy: Determine the distance between 2 odd reference point markers (reference point marker
interval). This value (which is 20.00 mm on Heidenhain scales) must be entered in the
machine data 34300 ENC_REFP_MARKER_DIST.
Check the reference point track of the scale including the electronics for the evaluation.
Program Con- Clear alarm with the RESET key. Restart part program
tinuation:
20004
Channel %1 axis %2 reference mark missing
Parameters: %1 = Channel number
%2 = Axis name, spindle number
Definitions: In the distance-coded length measurement system two reference marks were not found
within the defined searching distance (axis-specific MD: 34060
REFP_MAX_MARKER_DIST).
No reduction cam is required for distance-coded scales (but an existing cam will be evalu-
ated). The conventional direction key determines the direction of search. The searching
distance 34060 REFP_MAX_MARKER_DIST, within which the two reference point mark-
ers are expected is counted commencing at the start point.
Reactions: - NC Start disable in this channel.
- Interface signals are set.
© Siemens AG, 2005. All rights reserved
SINUMERIK 840D sl/840D/840Di/810D Diagnostics Guide (DA), 08/2005 Edition
Overview of Alarms
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