Siemens SINUMERIK 804D sl Commissioning Manual page 147

Notice
The axis affected must be re-referenced.
Encoder zero mark monitoring
The zero mark monitoring of the encoder of a machine axis checks whether pulses were lost
between two zero mark passes. Via
• MD36310 ENC_ZERO_MONITORING (Zero mark monitoring)
is used to enter the number of detected zero mark errors at which the monitoring is to
respond.
Special situation:
A value of 100 will additionally disable hardware monitoring of the encoder.
Error response
• Alarm: "25020 Zero mark monitoring"
and stopping the machine axes using a speed setpoint ramp whose characteristic is set in
• MD36610 AX_EMERGENCY_STOP_TIME (Time for braking ramp when an error occurs)
Cause of errors/error handling
• MD36300 ENC_FREQ_LIMIT [n] (encoder limit frequency) set too high.
• Encoder cable damaged.
• Encoder or encoder electronics defective.
Position tolerance when switching over the encoder
It is possible to switch between the two encoders or position measuring systems of a
machine axis at any time. The permissible position difference between the two position
measuring systems when switching over is monitored.
• MD36500 ENC_CHANGE_TOL (Max. tolerance on position actual value switchover)
Error response
• Alarm: "25100 Measuring system cannot be switched over"
The requested switchover to another encoder is not carried out.
Cause of errors/error handling
• The specified permissible tolerance is too small.
• The position measuring system to which you will switch over is not referenced.
Transmission Monitoring the encoder position tolerance
The position difference between the two encoders or position measuring systems of a
machine axis is monitored with
CNC Part 1 (NCK, PLC, drive)
Commissioning Manual, 11/2006, 6FC5397-2AP10-2BA0
NCK start-up
10.5 Parameterize axis data
147