Rockwell Automation 1771-QDC, D17716.5.86(Passport) PLASTIC MOLDING MODULE - Manual (Page 228)

Tune Your Machine
Chapter 10
10-20
You enter ramp rates in units of 0 to 9999 percent signal output per
second (note that there is no decimal point). A ramp rate of 9999 lets
the output move full range in 10 milliseconds, while a ramp rate of 99
requires a full second to go full range. Lower values = slower ramps.
Profile Watchdog Timer Preset
(PLC08)
Set your plastication profile watchdog timer preset after your machine is
running repeatable, quality parts. Set it just longer than the repetitive
duration of the profile to warn that a process problem may be developing.
For example, warn of a low feed level from the hopper.
Profile Offsets
(for velocity - IPC51)
(for pressure - IPC52, HPC25 and 42, PPC52)
The offset shifts the amplitude of all pressure or velocity setpoints (y-axis)
of a profile by a single value. Use it during set-up after you have obtained
the desired profile shape to boost or reduce the overall effect of the profile.
The QDC monitors process pressures and compare them against two
different types of high pressure alarm setpoints. Pressures are compared to
absolute pressure alarm setpoints (configured in the MCC - refer to
chapter 3) on a continuous basis and without regard to current machine
mode or operational cycle. Pressures are compared to profile pressure
alarm setpoints (configured in the respective configuration blocks - refer to
chapter 7) only during the execution of the subject profile. In general:
Use absolute pressure alarms to detect dangerously high pressure
conditions. We recommend these alarm setpoints be set well above
normal operating levels while still below levels that could result in
machinery damage or danger to personnel. Program your PLC-5 ladder
logic to stop the QDC module and place the machine in a safe condition
if one of these alarms is triggered
Use profile pressure alarms to detect abnormally high pressure
conditions. We recommend these alarm setpoints be set only marginally
above the highest pressure expected during any acceptable iteration of
the subject profile while still low enough to be indicative of process
problems. Program your PLC-5 ladder logic to interrupt the process or
signal the machine operator to determine corrective action if one of
these alarms is triggered
Watchdog Timer
and Profile Offsets
Pressure Alarm Setpoints