M40: Automatic Gear Stage Selection For Speeds Outside The Configured Switching Thresholds - Siemens SINUMERIK 828D Function Manual

16.8.9 M40: Automatic gear stage selection for speeds outside the configured switching
thresholds
Function
When M40 is active, an automatic gear stage selection is also made if the programmed spindle speed S... lies
outside the configured switching thresholds.
In this case, a distinction is made between the following cases:
• Programmed speed too high
The programmed speed is higher than the configured maximum speed of the numerically largest gear stage:
S... > MD35110 $MA_GEAR_STEP_MAX_VELO[<n>]
In this case, the highest gear stage is selected (according to MD35090 $MA_NUM_GEAR_STEPS).
• Programmed speed too low
The programmed spindle speed is less than the configured minimum speed of the first gear stage:
S... < MD35120 $MA_GEAR_STEP_MIN_VELO[1]
In this case, the first gear stage is selected.
• Programmed speed = 0
When programming speed 0 (S0) the behavior depends on the configuration of the minimum speed of the first
gear stage MD35120 $MA_GEAR_STEP_MIN_VELO[1]:
- If MD35120 $MA_GEAR_STEP_MIN_VELO[1] = 0 is configured, then when programming S0, the first
gear stage is selected.
- If MD35120 $MA_GEAR_STEP_MIN_VELO[1] > 0 is configured, when programming S0 no gear stage
change is performed and the last gear stage remains active. This means that it remains possible to stop
the spindle with S0 (instead of M5) without initiating a gear stage change.
Effectiveness
Selecting the highest gear stage or the first gear stage for automatic gear stage selection (M40) is active when
programming spindle speeds S... using the part program, in synchronized actions or when entering via PLC
FC18.
For speed programming from the part program for tapping with G331, the behavior is also supported for the
second data set to select the gear stage (precondition: MD35010 $MA_GEAR_STEP_CHANGE_ENABLE,
bit 5 = 1).
Boundary conditions
Enabling the gear stage change
The precondition for the function is that the gear stage change is generally enabled via machine data:
MD35010 $MA_GEAR_STEP_CHANGE_ENABLE (assign parameters to the gear stage change)
MD35090 $MA_NUM_GEAR_STEPS (number of gear stages set up)
Basic Functions
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
S1: Spindles
16.8 Spindle monitoring
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