4MELFA-BASIC IV
Detailed explanation of command words
4-190
(6) If the hand is facing downward, the sign of the A, B and C axis coordinates at the start point, end point A,
end point B and diagonal point must match. If the hand is facing downward, A = 180 (or -180), B = 0, and
C = 180 (or -180). If the signs of the A and C axis coordinates at the three positions do not match, the
hand may rotate in the middle position. In this case, modify the signs so that they match in the position
edit screen of the T/B. +180 and -180 result in the same posture; modifying signs poses no problem.
(7) If a value from 11 to 13 is specified for the pallet pattern, the posture at <Start Point> is assigned to the
posture data of the position variable obtained by the pallet operation. If a value from 1 to 3 is specified,
the distance between <Start Point> and <End Point> is divided equally and assigned to the posture data.
If position data whose posture components (A, B and C) are close to +/-180
degrees is set to <Start Point>, <End Point A>, <End Point B> and <Diagonal
Point> of the pallet definition, the hand will rotate and move in unexpected ways if
different signs are used for the same posture component of the position data.
To use position data whose posture components are close to +/-180 degrees,
please read
<Precautions on the posture of position data in a pallet definition>
in
Page 98, "4.1.2 Pallet operation"
.
The value of the start point of the pallet definition is employed for the structure flag
of grid points (FL1 of position data) calculated during pallet operation (Plt instruc-
tion). For this reason, if position data with different structure flags are used for each
point of the pallet definition, the desired pallet operation cannot be obtained.
Use position data whose structure flag values are all the same for the start point,
end points A and B and the diagonal point of the pallet definition. The value of the
start position of the pallet definition is employed for the multi-rotation flag of grid
points (FL2 of position data) as well. If position data with different multi-rotation
flags are used for each point of the pallet definition, the hand will rotate and move in
unexpected ways depending on the robot positions the pallet operation goes
through and the type of interpolation instruction (joint interpolation, line interpola-
tion, etc.). In such cases, use the TYPE argument of the interpolation instruction to
set the detour/short cut operation of the posture properly and ensure that the hand
moves as desired.
Please refer to the illustrations in
Page 98, "4.1.2 Pallet operation"
, which explain this concept.
[Related instructions]
CAUTION
CAUTION