Yaskawa SMC–4000 - Manual (Page 286)

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SMC–4000 User Manual
Additional Commands
The commands VS n, VA n and VD n are used for specifying the vector speed, acceleration, and
deceleration. VT is the motion smoothing constant used for coordinated motion.
Specifying Vector Speed for Each Segment:
The vector speed may be specified by the immediate command VS. It can also be attached to a motion
segment with the instructions
VP x < n >m
The first parameter, <n, is equivalent to commanding VSn at the start of the given segment and will cause
an acceleration toward the new commanded speeds, subject to the other constraints.
The second parameter, > m, requires the vector speed to reach the value m at the end of the segment. Note
that the function > m may start the deceleration within the given segment or during previous segments, as
needed to meet the final speed requirement, under the given values of VA and VD.
Note, however, that the controller works with one > m command at a time. As a consequence, one
function may be masked by another. For example, if the function >100000 is followed by >5000, and the
distance for deceleration is not sufficient, the second condition will not be met. The controller will
attempt to lower the speed to 5000, but will reach that at a different point.
Changing Feedrate:
The command VR n allows the feedrate, VS, to be scaled from 0 to 10 times with a resolution of .0001.
This command takes effect immediately and causes VS to be scaled. VR also applies when the vector
speed is specified with the ‘<’ operator. This is a useful feature for feedrate override. VR does not ratio
the accelerations. For example, VR .5 results in the specification VS 2000 to act as VS 1000.
Trippoints:
The AV n command is the After Vector trippoint, which waits for the vector relative distance of n to occur
before executing the next command in a program.
Tangent Motion:
Several applications, such as cutting, require a third axis (i.e. a knife blade), to remain tangent to the
coordinated motion path. To handle these applications, the SMC–4000 allows one axis to be specified as
the tangent axis. The VM command provides parameter specifications for describing the coordinated axes
and the tangent axis.
V,M m,n,p m,n specifies coordinated axes, p specifies tangent axis such as A,B,C or
D p=N turns off tangent axis
Before the tangent mode can operate, it is necessary to assign an axis via the TN m,n command. m defines
the scale factor in counts/degree and n defines the tangent position that equals zero degrees in the
coordinated motion plane. The operand _TN can be used to return the initial position of the tangent axis.