Siemens SINUMERIK 840D sl Function Manual page 78

Detailed description
2.1 Axis monitoring
2.1.2.3 Zero speed monitoring
Function
At the end of a positioning operation:
• Set velocity = 0 AND
• DB31, ... DBX64.6/64.7 (motion command minus/plus) = 0
checks the zero-speed monitoring to ensure that the following error of every participating
machine axis is smaller than the standstill tolerance during the delay time.
MD36040 $MA_STANDSTILL_DELAY_TIME (Zero-speed monitoring delay time)
MD36030 $MA_STANDSTILL_POS_TOL (standstill tolerance)
After reaching the required exact-stop state, the positioning operation is completed:
DB31, ... DBX60.6/60.7 (position reached with exact stop coarse/fine) = 1
The position-monitoring function is deactivated and is replaced by the zero-speed
monitoring.
Zero-speed monitoring monitors the adherence to the standstill tolerance. If no new travel
request is received, the machine axis must not depart from the standstill tolerance.
Effectivity
The zero-speed monitoring only operates with active position control and the following axis
types:
• Linear axes
• Rotary axes
• Position-controlled spindles
Fault
If the delay time and/or the standstill tolerance is exceeded, the following alarm appears:
25040 "Axis <Axis identifier> Zero-speed monitoring"
The affected axis is stopped via the configured braking ramp in follow-up mode:
MD36610 $MA_AX_EMERGENCY_STOP_TIME
(Maximum time for braking ramp when an error occurs)
12
Basic logic functions: Axis monitoring, protection zones (A3)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0