VP -37600,-16000
Return XY to start
VE
VS 200000
BGS
AMS
EN
Figure 7.2: Motor Velocity and the Associated Input/Output signals
Speed Control by Joystick
The speed of a motor is controlled by a joystick. The joystick produces a signal in the range between -10V and
+10V. The objective is to drive the motor at a speed proportional to the input voltage.
Assume that a full voltage of 10 Volts must produce a motor speed of 3000 rpm with an encoder resolution of
1000 lines or 4000 count/rev. This speed equals:
3000 rpm = 50 rev/sec = 200000 count/sec
The program reads the input voltage periodically and assigns its value to the variable VIN. To get a speed of
200,000 ct/sec for 10 volts, we select the speed as:
Speed = 20000 x VIN
The corresponding velocity for the motor is assigned to the VEL variable.
Instruction
#A
JG0
BGX
#B
VIN=@AN[1]
VEL=VIN*20000
JG VEL
JP #B
EN
Position Control by Joystick
This system requires the position of the motor to be proportional to the joystick angle. Furthermore, the ratio
between the two positions must be programmable. For example, if the control ratio is 5:1, it implies that when the
joystick voltage is 5 Volts, corresponding to 1028 counts, the required motor position must be 5120 counts. The
variable V3 changes the position ratio.
Chapter 7 Application Programming ▫ 141 DMC-41x3 User Manual
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