Red Lion GEMINI 33 - Manual (Page 10)

INPUT CIRCUITRY & SET-UP
There are two independent input channels on the Gemini 3300. Various
types of sensor outputs can be accommodated by appropriate DIP switch
set-up. These include: TTL or CMOS logic, current sinking, current sourcing,
or dry contact and more.
Channel A consists of a logic input and a separate low level magnetic
pickup input.
Channel B is a completely independent count or control input channel.
Like Channel A, it can be programmed with DIP switches for a wide variety of
logic inputs, and is identical to Channel A in this regard. For a complete
detailed description of input set-up, see Appendix “A”.
OVERFLOW INDICATION
The Gemini 3300 features an overflow indicator (LED) which is located to
the left of the sixth digit and above the polarity annunciator. This LED will turn
on if the capacity of the display (6-digits) is exceeded or if the internal count
capacity (9-digits, 7 digits for batch counter) is exceeded. Use of extremely
small scale multiplier and Scale Factor Value can cause the internal count
(Process and Total) capacity to overflow before the displayed value would
overflow. For example, if a Scale Factor of 0.0001 and a Scale Multiplier of
0.001 is used, for every 10,000,000 count edges received, the display would
increment by 1. Before the display reaches 215, the internal counter would
overflow. When the capacity of the display is exceeded, the count value will be
maintained and will be valid. But if the internal count capacity is exceeded,
then this value will no longer be valid. The internal Process and Total count
values will overflow after 2,147,483,647 counts have been entered. The count
information will become invalid after 4,294,967,295 counts. At this point the
counter will change sign and the displayed count will decrement in value.
The internal count capacity for the Batch Counter is 16,777,216. This
amounts to overflowing the Batch Counter display over 16 times. If this
number is exceeded, the counter will rollover to zero, however, the displayed
digits will no longer be valid. It should also be noted that the use of a Scale
Factor larger than one could cause the displayed Process or Total value to
overflow before 999,999 counts are accumulated.
The Batch and Totalizing counters should not be allowed to operate in the
overflowed condition. As soon as, or before the counters overflow, the
information should be recorded and the counters reset.
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