Graco 3A2098H On/Off Delays, Delay On/Off Timing, On/Off Delay Variables. For instructions set

									System Setup
On/Off Delays				FIG. 29 and Table 6: Delay On/Off Timing show delay
				ON and OFF timing.
The PCF fluid regulator can physically respond faster				Table 6: Delay On/Off Timing
than the dispense device and its solenoid. As a result,
the fluid regulator can supply material to the dispense				A	Regulator ON		The user sets the fluid regu-
device before the device has time to open. Supplying					delay		lator ON delay timing.
material to a closed device can create trapped-pressure.
				B	Valve ON delay		Usually set to zero. Can be
At the end of a cycle, the dispense device can shut off							used to change the starting
							point of a bead.
before the pressure has dissipated. This can cause a
				C	Valve OFF Delay		Usually set to zero. Higher
dispense of an excess of material at the beginning of the
							values will lower the trapped
next cycle.
							pressure.
To eliminate these two problems, change the delay time
				D	Regulator OFF		The user sets the regulator
associated with the opening of the fluid regulator/dis-					delay		OFF delay timing. Zero or
pense and/or the closing of the dispense device, see							small values will lower the
Table 5: On/Off Delay Variables. For instructions set-							trapped pressure.
ting on/off delays, see Configure Delay Settings, page
				E	Valve Open		Time delay for valve to phys-
34.
					Reaction Time		ically open. Delay varies
NOTE: On/Off delay can be set for each dispense							based on pneumatic hose
							length and valve air volume.
device.
				F	Valve Close		Time delay for valve to phys-
In general, delays should be adjusted so the outlet pres-					Reaction Time		ically close. Delay varies
							based on pneumatic hose
sure during “no flow” is slightly below the outlet pressure
							length and valve air volume.
during dispense.
Table 5: On/Off Delay Variables
Variable:	Sets the Amount of Time:
Valve ON	Sets time from Dispense Valve High
	to Valve Open command
Regulator	Sets time from Dispense Valve High
ON	to Regulator ON
Valve OFF	Sets time from Dispense Valve Low
	to Valve Close command
Regulator	Sets time from Dispense Valve Low
OFF	to Regulator OFF
Dispense Valve								C
Signal			A
Fluid								D
Regulator
Valve Open			B
Command
Valve Actually		E
Open						F
FIG. 29: Timing Delay

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