Siemens SINUMERIK 840D sl Series Diagnostics Manual page 378

Overview of Alarms
Parameters: %1 = Axis name, spindle number
Definitions: The prerequisites are not satisfied for the required encoder switchover:
1. The newly selected encoder must be in the active state (DB 31 - 48, DBX 1.5 or 1.6 = 1
"Position measuring system 1/2")
2. The actual value difference between the two encoders is greater than the value in the
axis-specific MD 36500 ENC_CHANGE_TOL ("Maximum tolerance for position actual
value switchover").
Activation of the measuring system concerned takes place in accordance with the inter-
face signals: "Position measuring system 1" (DB 31 - 48, DBX 1.5) and "Position measur-
ing system 2" (DB 31 - 48, DBX 1.6), i.e. the position control is now operated with this
measuring system. The other measuring system is switched over to follow-up mode. If
both interface signals are set to "1", then only the 1st measuring system is active; if both
interface signals are set to "0", the axis is parked.
Changeover takes place as soon as the interface signals have changed, even if the axis
is in motion!
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. When referencing the active
position actual value encoder, the actual value system of the inactive encoder is set to the
same reference point value as soon as phase 3 has been concluded. A later positional
difference between the 2 actual value systems can have occurred only as the result of an
encoded defect or a mechanical displacement between the encoders.
• Check the encoder signals, actual value cable, connectors.
• Check the mechanical fastenings (displacement of the measuring head, mechanical
twisting possible).
• Increase the axis-specific MD 36500 ENC_CHANGE_TOL.
Program continuation is not possible. The program must be aborted with "Reset", then
program execution can be reinitiated with NC Start, if necessary at the interruption point
after "Block search with/without calculation".
Program Con- Clear alarm with the RESET key. Restart part program
tinuation:
25105
Axis %1 measuring systems differ considerably
Parameters: %1 = Axis name, spindle number
Definitions: The two measuring systems differ considerably, i.e. the cyclically monitored actual value
difference between the two measuring systems is greater than the associated tolerance
value set in the machine data $MA_ENC_DIFF_TOL. This can only occur when both
measuring systems are active ($MA_NUM_ENCS = 2) and referenced. The alarm can be
reprogrammed in the MD ALARM_REACTION_CHAN_NOREADY (channel not ready).
Reactions: - Mode group not ready.
- The NC switches to follow-up mode.
- Channel not ready.
- NC Start disable in this channel.
- Interface signals are set.
- Alarm display.
- NC Stop on alarm.
- Channel not ready.
Remedy: Please inform the authorized personnel/service department. Check machine data for the
active, selected encoders. Check the machine data relating to encoder
($MA_ENC_DIFF_TOL) tolerance.
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SINUMERIK 840D sl/840D/840Di/810D Diagnostics Guide (DA), 08/2005 Edition
© Siemens AG, 2005. All rights reserved
08/2005