User`s guide

directs the robot to perform a straight-line motion to location loc_1, which is specified
relative to the location defined by the belt variable %belt. If a belt variable is specified, it
must be the first (that is, leftmost) element in a compound transformation. Only one belt
variable can appear in any compound transformation.
Motions relative to a belt can be only of the straight-line type. Attempting a joint-
interpolated motion relative to a belt causes an error and halts execution of the application
program. Except for these restrictions, motion statements that are defined relative to a belt
are treated just like any other motion statement. In particular, continuous-path motions
relative to belts are permitted.
Once the robot has been moved to a destination that is defined relative to a belt, the robot
tool will continue to track the belt until it is directed to a location that is not relative to the
belt. For example, the following series of instructions would move the tool to a location
relative to a belt, open the hand, track the belt for two seconds, close the hand, and finally
move off the belt to a fixed location.
MOVES %belt[1]:location3
OPENI
DELAY 2.00
CLOSEI
MOVES fixed.location
If this example did not have the second MOVES statement, the robot would continue to track
the belt until a belt window violation occurred.
As with motions defined relative to a belt, motions that move the tool off a belt (that is, to a
fixed location) must be of the straight-line type.
Motion Termination
When moving the robot relative to a belt, special attention must be paid to the conditions
used to determine when a motion is completed. At the conclusion of a continuous-path
motion V+ normally waits until all the joints of the manipulator have achieved their final
destinations to within a tight error tolerance before proceeding to the next instruction. In
the case of motions relative to a belt, the destination is constantly changing and, depending
upon the magnitude and variability of the belt speed, the robot may not always be able to
achieve final positions with the default error tolerance.
Therefore, if a motion does not successfully complete (that is, it is aborted due to a Time-out
nulling error), or if it takes an excessive amount of time to complete, the error tolerance for
the motion should be increased by preceding the motion instruction with a COARSE
instruction. In extreme situations it may even be necessary to entirely disable checking of
the final error tolerance. This can be done by specifying NONULL before the start of the
motion.
Basic Programming Concepts
(Undefined variable: Primary.Product_Name_V)Language User's Guide, version
17.x
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