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special circumstances can be used with continuous or bar stock fed headers or other such
applications. NOFEEDs can be OFF, CONSecutuve, or CUMUlative. “CUMU” stands for
cumulative. This means that IMPAX will allow a certain number of errors out of 100 to be
ignored. For example, if I set the number to 2, IMPAX would allow 2 parts out of 100 to exceed
either the HI or the LO limit without shutting down the machine.
“CONS” stands for consecutive. This means that IMPAX will allow a certain number of errors
in a row to be ignored. For example, if I set the number to 2, IMPAX would allow 2 errors in a
row but the 3rd error in a row would cause the machine to stop. When tuning the IMPAX unit, it
is often helpful to set a large number of exceptions, say 10 or 15 and watch the force values in
the Error/Exceptions buffer. This can tell you what the values were for the exceptions and can
give you information needed to establish the proper settings for the tolerances. Press Next/No to
select one of the choices, then press Enter/Yes to lock it in.
The next display is "NOFEED EXC OFF" OR "NOFEED EXC ON." No Feed Exceptions is a
special feature which will divert a certain number of parts immediately after a No Feed
condition. This may be used if, for example, there were several consecutive no feeds and the
dies cooled off. The first ten parts may not be as good quality as those produced after the dies
heated up. No Feed Exceptions could be set to eject these parts if they did not meet the tolerance
parameters.
The next display is "IMMED LIM OFF" or "IMMED LIM ON." Immediate Limits enables the
fastest protection possible. This is useful because you may not want your machine to go
unprotected for 120 parts every time the machine stops and goes through another LEARN cycle.
IMMEDIATE LIMITS limits the LEARN cycle to only four parts. It takes the force values from
the last good part and stores them in memory. When the machine starts back up, it compares the
average force values of the first four parts to these stored values, and if the values are the same,
the machine will jump into run mode. If the first few parts during this “IMMEDIATE” cycle are
not consistent, the IMPAX monitor will shut the machine down again. Also, IMMEDIATE
limits cannot be used anytime the machine is cold or when there is a tool change. This is
because the force values in memory will not be the same as the ones when the machine is started
up and the IMPAX monitor will keep shutting down the process. Press Next to select your
choice, then press Enter/Yes.
The next display will be: “LO + HI LIMITS”, “LO LIMIT ONLY”, or “HI LIMIT ONLY”.
This option should normally left at LO + HI LIMITS and should only be changed for special
circumstances. One of the special circumstances is “Splitting the Channels” which will be
discussed in the Section on Advanced Operator Functions. Press Next/No to change this option
and then press Enter/Yes when you have found your choice.
The next display shows “LIMITS ON SLMH”. The SLMH indicates which of the limit tests are
activated for this channel. The IMPAX monitor performs four limit tests for every blow by
retaining in memory the learned force limits from the previous stroke. It then compares that
value in memory to the value of the current stroke and that is called the “Single Hit Limit.” The
IMPAX monitor can also compare the learned value of the last four (4) strokes and that limit is
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