System Setup
3A2098S 43
On/Off Delays
The PCF fluid regulator can physically respond faster
than the dispense device and its solenoid. As a result,
the fluid regulator can supply material to the dispense
device before the device has time to open. Supplying
material to a closed device can create trapped-pressure.
At the end of a cycle, the dispense device can shut off
before the pressure has dissipated. This can cause a
dispense of an excess of material at the beginning of the
next cycle.
To eliminate these two problems, change the delay time
associated with the opening of the fluid
regulator/dispense and/or the closing of the dispense
device, see Table 5: On/Off Delay Variables. For
instructions setting on/off delays, see Configure Delay
Settings, page 38.
NOTE: On/Off delay can be set for each dispense
device.
In general, delays should be adjusted so the outlet
pressure during “no flow” is slightly below the outlet
pressure during dispense.
Table 5: On/Off Delay Variables
F
IG. 32 and Table 6: Delay On/Off Timing show delay
ON and OFF timing.
Table 6: Delay On/Off Timing
Variable: Sets the Amount of Time:
Valve ON Sets time from Dispense Valve High
to Valve Open command
Regulator
ON
Sets time from Dispense Valve High
to Regulator ON
Valve OFF Sets time from Dispense Valve Low
to Valve Close command
Regulator
OFF
Sets time from Dispense Valve Low
to Regulator OFF
A Regulator ON
delay
The user sets the fluid
regulator ON delay timing.
B Valve ON delay Usually set to zero. Can be
used to change the starting
point of a bead.
C Valve OFF Delay Usually set to zero. Higher
values will lower the trapped
pressure.
D Regulator OFF
delay
The user sets the regulator
OFF delay timing. Zero or
small values will lower the
trapped pressure.
E Valve Open
Reaction Time
Time delay for valve to
physically open. Delay
varies based on pneumatic
hose length and valve air
volume.
F Valve Close
Reaction Time
Time delay for valve to
physically close. Delay
varies based on pneumatic
hose length and valve air
volume.
FIG. 32: Timing Delay
D
C
A
B
Dispense Valve
Signal
Fluid
Regulator
Valve Open
Command
Valve Actually
Open
E
F
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