Automation Control (Normal) Operation; Jobs - Graco PCF Instructions And Parts

Operation
Automation Control (Normal)
Operation
During automation control (normal operation) the mod-
ule automatically dispenses when it receives a com-
mand from the automation unit.
The automation control operates using the concept of
jobs and styles. For a detailed explanation of jobs and
how they work within the PCF system, see Jobs on
page 40. For a detailed explanation of styles and how
they work within the PCF system, see Styles on page
41.

Jobs

NOTE: See Appendix D - I/O Signal Descriptions,
page 104, for automation input and output signal
descriptions.
A job is a specified amount of material that is dispensed
by the system. The amount of material specified for a
job varies, depending on the application. In some appli-
cations, a job may be the amount of material dispensed
on a part. Other applications may define a job to be the
amount of material dispensed on a number of parts or
dispensed over a period of time.
A job is initiated when the automation sends a Style
Strobe signal to the PCF. Once the job is initiated, the
PCF will start tracking the amount of volume requested
by the automation and the amount of material that is
actually dispensed. These volumes will be tracked until
the job is completed. At the end of the job, fault calcula-
tions are made and the volumes are stored to non-vola-
tile memory on the PCF system (Job Log).
The PCF system monitors two things to determine when
a job is complete. Either the Dispense Complete signal
is sent by the automation or the job complete timer
expires. The type of job end signal is configured in the
Fluid Plate Control Settings screen to Timer or Gateway.
If the timer method is used, the timer begins counting
every time the dispense gun is turned off. If the gun
stays off for more than the preset timer value, the job is
considered complete.
Once the job is complete, the job information is stored to
memory. The most recent jobs can be viewed on the Job
screen. The information stored with each job is as fol-
lows. See Job Report Screens, page 92, for instruc-
tions on how to view job reports.
40
Actual (Measured) Volume - The amount of material
measured by the flow meter during a job.
Requested Volume - The amount of material that the
automation tries to dispense during a job. This volume is
calculated by measuring how long the dispense gun is
on, taking in effect the command voltage from the auto-
mation over time.
Target Volume - The theoretical amount of material that
a job should have. This value is usually calculated or
found using trial and error when the application is first
set up.
Jobs in Bead Mode
In Bead Mode, all of these volumes are monitored. The
High Volume, Low Volume, and Computed Target faults
are evaluated at the end of the job. The volume alarms
compare the measured volume to the requested volume
and the computed target alarm compares the requested
volume to the target volume.
Jobs in Pressure Mode
In Pressure Mode, the requested volume is not mea-
sured. In this mode, the automation command voltage
corresponds to a pressure instead of flow rate. For this
reason the requested volume is not available (as well as
the Computed Target fault). The high and low volume
alarms compare the measured volume to the target vol-
ume for pressure mode.
Continuously Running Applications
In some cases the target volume for a job is not known.
An example of a case where the target volume is
unknown is a continuously running system. This would
be a system that does not run jobs, but runs continu-
ously over a day or a shift. In this case, the flow rate
becomes more important than the amount of volume
dispensed in a job. The way to handle this situation is to
set the target volume to a value of zero. This effectively
disables the computed target fault. The controls will still
maintain the desired flow rate and report faults corre-
sponding to the tolerance set for the running style
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