19
User Manual
Model PCS
Pneumatic Motion Control System
If neither LED
is on - (Span is currently set somewhere in mid-stroke.) Slowly adjust the Span potentiometer
CCW to move the actuator rod or shaft toward the full scale position. When the actuator hits the full scale
position, the green LED will continue to flicker even when the adjustment is no longer being turned. Now adjust
the Span CW just enough to turn off the green LED. Both LEDs should be off when set correctly. This ends the
Preliminary Span adjustment.
15. FINAL “ZERO” AND “SPAN” ADJUSTMENT
The Zero and Span adjustments may need to be fine tuned. This is accomplished by setting the Main control
to the zero position signal (0 volts, 0 mA, or 4 mA) and repeating Step 12, being careful to make very small
adjustments, as the setting should already be very close. Now recheck Step 13 and make any small adjustment
that may be necessary.
This completes the final Zero and Span adjustments.
16. “DECEL” RANGE ADJUSTMENT
Low Decel settings provide fastest speeds. High Decel settings provide the most stability for high loads. If
deadband is set too low for the load, the rod will overshoot and undershoot the target position, oscillating
before settling to a stop. The default setting is 1.5 volts. But it can be varied from 0.5 to 13.5 volts. To adjust
the Deceleration Range, rotate the DECEL potentiometer as shown in the photo below and monitor the voltage
between TP1 and TP3.
TP1
TP3
Decel
Decel adjustment
