Siemens SINUMERIK 840Di Function Manual page 217

2.2 Constant travel time (channel-specific)
2.2
2.2.1 Detailed description
2.2.1.1 General information
Key statement
In the case of acceleration without jerk limitation, sudden acceleration of 2 * a
switchover between acceleration and braking. In order to avoid this sudden acceleration, a
channel-specific constant travel time can be programmed. The constant travel time defines
the time taken to traverse between the acceleration and braking phases at constant velocity:
MD20500 $MC_CONST_VELO_MIN_TIME (minimum time with constant velocity)
Note
The constant travel time is ineffective:
• Active function: Look Ahead
• In traversing blocks with a travel time that is less or equal to the interpolation cycle time.
Fig. 2-2
Acceleration (B2)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0
Schematic for abrupt acceleration
Detailed Description
2.2 Constant travel time (channel-specific)
occurs on
max
2-5