Siemens SINUMERIK 840Di Function Manual page 89

Effectivity
The encoder limit frequency always refers to the active measuring system selected in the
NC/PLC interface:
DB31, ... DBX1.5 / 1.6 (position measuring system 1 / 2)
The encoder limit frequency is operative for:
• Linear and rotary axes
• Open loop controlled and position controlled spindles
Effect
Upon exceeding of the encoder limit frequency, the following occurs:
• Message to the PLC
• Spindles
• Axes
Axis Monitoring, Protection Zones (A3)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0
DB31, ... DBX60.2 or 60.3 = 1 (encoder limit frequency exceeded 1 or 2)
Spindles are not stopped but continue to turn with speed control.
If the spindle speed is reduced so much that the encoder frequency passes below the
encoder limit frequency, the actual value system of the spindle is automatically
resynchronized.
– Alarm: "21610 Channel <
number
> Frequency exceeded"
– The affected axis is stopped via the configured braking ramp in follow-up mode:
MD36610 $MA_AX_EMERGENCY_STOP_TIME
(Time for braking ramp when an error occurs)
– If the axis/spindle is involved in interpolation with other axes/spindles, these are brought
to a standstill with rapid stop (set velocity = 0).
After the axis have stopped, the position control is automatically resumed.
Note
If the encoder limit frequency is exceeded, the position-controlled machine axis must be
re-referenced.
References:
/FB/ Description of Functions Basic Machine; Reference Point Approach (R1)
Channel number
> Axis <
Detailed Description
2.2 Encoder monitoring
Axis identifier
> Encoder <
Encoder
2-17