Red Lion LEGEND - Manual (Page 70)

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APPENDIX “C” - APPLICATION
A local canning plant wishes to improve the display and control capabilities
of its nine process lines. There is a requirement to add message interaction for
the operators as the process progresses. The following application facts and
requirements have been specified by the customer.
1. The cans are sensed by a photo-electric device specially suited for can
manufacturing. The device produces one pulse per can. The canning line
never reverses, and any jitter problems at the sensing point are corrected
by the photo device.
2. The can count for the process of boxing the cans is the first requirement. The
can count is never changed, there are always 24 cans to each box. An output is
required at 20 cans to slow the line temporarily until the second output is
turned on. The second output changes the gate direction to begin the next
grouping of 24. The second output has a time delay output of 2 seconds. After
the time delay, both outputs are reset and ready for the next process cycle.
3. A count of the number of batches is required for each 8-hour shift. This count
is recorded and reset by the manufacturing computer.
4. A total count of cans produced per 24-hour period is required. This count is
also transmitted to the manufacturing computer, and reset as required via the
communication link.
5. A display of cans per minute is required with minimum and maximum speed
limits. Output 3 activates below 100 counts per minute and Output 4
activates above 500 counts per minute.
6. The four desired displays are process, batch, total, and rate. These are to be
scrolled via the front panel.
7. The customer also wants the following messages displayed when the listed
events occur:
Output 3 - Line #4 Slow
Output 4 - Overspd STOP! (Wants this display to stand out and have top
priority)
Proximity 1 - Check Label Glue
Proximity 2 - Check Top Supply
Proximity 3 - System Fault! Stop Line #4! (Wants this display to stand out
and have top priority)
8. Once the unit is set up, the only front panel access should be for a reset of the
process count and viewing of the displays.
The following is a chart of the necessary programming as entered into the
Legend Plus unit.