Electro Cam PS-6144 Series - Manual (Page 59)

4-1 Speed Compensation
Introduction To Speed Compensation
What Is It? “Speed compensation” refers to the ability of the PS-6144 controller to automatically
advance or retard setpoints in any output channel depending on the speed of the ma-
chine. Speed compensation allows devices with fixed response times, such as glue
guns, to perform their functions with high accuracy over a wide range of machine speeds.
Without speed compensation, a glue bead may tend to “drift” out of position as machine
speed increases. By properly programming speed compensation for the output chan-
nel controlling the glue gun, the glue bead position can be maintained precisely over
the complete range of machine speeds.
Benefits Proper use of speed compensation can provide substantial benefits:
• Increased Productivity—If a machine incorporates components with fixed response
times, the use of speed compensation can often increase line speeds by as much as
50%.
• Reduced Scrap Rate—Speed compensation maintains the accuracy of critical oper-
ations such as gluing, thereby reducing rejects, rework, and scrap.
• Simplified PLC Systems—Programming speed compensation into standard motion
control equipment such as PLC’s, stepper motors, and stepper motor controls is dif-
ficult. In addition, to perform speed compensation at high machine speeds, the PLC
hardware must be extremely fast, and therefore expensive. Integrating a PS-6144
into the control system eliminates the need to write custom PLC speed compensation
programming, and provides excellent high speed control at a fraction of the hardware
cost.
Fixed Response Times Electromechanical components of automated systems often have fixed response times
regardless of the line speed. For example, a glue gun may require ten milliseconds
from the time the gun is actuated to the time that glue begins flowing. At the slowest line
speed, the gun might need to be triggered when the carton is one inch away, so that the
carton arrives under the gun just as glue begins flowing. As the line speed increases
and the product travels faster, the lead distance from the carton to the gun must in-
crease in order for the gun, with its fixed response time, to still hit the correct spot on the
product. By programming speed compensation into the PS-6144, the timing of glue
guns and similar mechanisms can be automatically advanced as speed increases, main-
taining proper operation over a wide range of machine speeds.
NOTE: Regardless of the number of outputs available, speed compensation is limited
to any 16 of those available outputs.