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Figure 12.11 - Sequential Instruction Form for Programming of Analog Absolute
Position Control
In figure 12.11 the scale factor is programmed for a value of 0.455
inches / volt and the offset for 1.0 inches at zero volts. Thus, an
analog input in volts times 0.455 plus 1.0 will correspond to the
absolute command position. In this example, physical input #002 is
chosen as the exit flag. If and when input #002 is logic state 1, this
instruction will terminate, motion tracking of the analog input will
stop and the system will decelerate to a stop. Execution of the next
sequential instruction will then commence.
ANALOG INPUT VELOCITY MODE
These sequential instructions allow control of motion velocity based
on the value of the analog input.
This functionality could be used for jogging or "joy-stick" type
operation modes with the analog input acting as the velocity
command source.
Another possible use would be to control torque or thrust according
to analog feedback from a force or torque transducer. This could be
done by programming the instruction to produce a velocity
proportional to the "error" between desired analog feedback
12-13
P R O G R A M M I N G : 1 2
