Danaher Motion 06/2005 Groups
M-SS-005-03 Rev E 123
6. 5 VELOCITY
A group’s scalar velocity properties are always the orthogonal combination of
the respective axes' velocity properties. Group velocity properties include:
VELOCITYCOMMAND vector property
VELOCITYFEEDBACK vector property
VELOCITYCRUISE scalar property
VELOCITYFINAL scalar property
VELOCITYMAX scalar property
VELOCITYOVERRIDE scalar property
Each of these properties operates as its axis equivalent and are clearly
defined in the SERVOSTAR
®
MC Reference Manual.
6. 6 LIMITS
Group limits are similar to limits placed on axes. Limits can be imposed in
two ways: they can be checked realtime, or they can be checked only for
subsequent actions.
6.6.1. Generator
Generator limits affect subsequent commands to the motion generator. For
example, if you change an acceleration limit, this affects subsequent motion
commands but has no effect on the current motion.
6.6.2. Realtime
The MC checks realtime limits each SERCOS update cycle. For example,
exiting position error of every axis is monitored each SERCOS cycle.
6.6.3. Position
Position limits are imposed solely by the axes and are checked at the
beginning of every movement. If one of the target’s points exceeds its limit,
the whole movement is rejected. There are no group position limits. There
are also several limits in the MC related to position:
Set POSITIONERRORMAX (PEMAX) to the total position error the system
can tolerate during operation (maximum square root of the sum of squares):
MyGroup.PEMax = 1.0
Set POSITIONERRORSETTLE to the total position error the system can
tolerate to be considered in position.
MyGroup.PositionErrorSettle = 1.0
TIMESETTLE (TSETTLE) is the amount of time required before an axis is
considered settled (POSITIONERROR<POSITIONERRORSETTLE). After a
MOVE/CIRCLE profile is complete, the MC waits for POSITIONERROR <
POSITIONERRORSETTLE for TIMESETTLE milliseconds before setting
ISSETTLED.
TIMESETTLEMAX (TSETTLEMAX) defines the amount of time allowed for
settling after a move has been commanded. After the MOVE/CIRCLE profile
is complete, the MC waits TIMESETTLEMAX milliseconds for settling. If the
position error remains above PESETTLE, an error is generated.
