Red Lion GEMINI 33 - Manual (Page 4)

GENERAL DESCRIPTION
The Gemini 3300 is a two input, microprocessor-based Batch Counter with
two Process Presets, a Batch Preset, and corresponding outputs. The 6-digit
display features 0.56" LEDs with negative sign, overflow, display mode, and
Process output indicators. The unit is available with a 20 mA Current Loop
Communications Option, which makes possible remote or computerized
monitoring and modification of the Count Values, Presets and Scale Factor.
Flexibility and usefulness are provided through user programmability.
With simple front panel keystrokes and rear panel switch settings, any one of
a number of configurations can be selected. Once the selection is made, all or
part of the keyboard can be disabled to protect the settings and guarantee that
no unwanted changes occur during the measurements.
Each time the power is turned off, the unit automatically saves the settings
and data in its special no power memory. When power is restored, the Gemini
sets itself back to the operational modes and restores the data it had at
power-down. The “no power” E 2 PROM’s life expectancy is at least 100,000
cycles of power being applied to and removed from the unit.
Whenever the power comes on, the Gemini 3300 performs a series of
internal diagnostics to verify the integrity of the stored data. There is also a
self-test mode and a “watchdog” timer to help prevent processor lockup.
The Gemini 3300 can accept uni-directional, bi-directional, or quadrature
signals. It also has the capability to double or quadruple (Quadrature x4) the
resolution of the incoming count signal. There are also modes available for
anti-coincidence applications. Both channels of count information are
monitored simultaneously, no counts are lost, and the final output can be
chosen as the sum or difference of the two input channels.
The Gemini 3300 20 mA Current Loop Communications option provides
the capability of two-way serial communications between the Gemini 3300
and a variety of equipment, such as a printer, remote terminal, programmable
controller, or host computer. The baud rate can be set to 300, 600, 1200, or
2400 baud. The format for transmitted and received data is 1 start bit, 7 data
bits, 1 parity bit (odd), and a stop bit. When utilizing an external power supply
(30 VDC max), up to sixteen units can be installed in the loop, each with an
individual address. When utilizing the Gemini’s 20 mA current source, up to
seven units can be installed in a loop. The Count Values, Presets, and Scale
Factor can be interrogated or changed by sending the proper command codes
and numerical data (if required) to the unit. Other functions, such as resetting
the various counters, can also be performed. Various “Print Options” can be
selected to automatically interrogate the Count Values, Presets, and Scale
Factor by activating the “Print Request” terminal or by sending a “Transmit
Per Print Option” (P) command.
The relays are mounted on a plug-in board which makes it easy to field
upgrade the Gemini 3300. The contacts are rated for 240 VAC or 28 VDC at
5 amps.
The construction of the Gemini 3300 features a metal die-cast bezel,
offering maximum durability with a high quality appearance. The sealed
front panel meets NEMA 4/IP65 specifications for washdown and/or dust
when properly installed. Clamp type pressure plate terminals accept stripped
#14 AWG wire without lugs.
SAFETY SUMMARY
All safety related regulations, local codes and instructions that appear in
the manual or on equipment must be observed to ensure personal safety and to
prevent damage to either the instrument or equipment connected to it. If
equipment is used in a manner not specified by the manufacturer, the
protection provided by the equipment may be impaired.
Do not use this unit to directly command motors, valves, or other actuators
not equipped with safeguards. To do so, can be potentially harmful to persons
or equipment in the event of a fault to the unit.
BASIC OPERATION
The Gemini 3300 contains three counters that keep track of the Process
Count, Batch Count, and Total Count. When a count edge is received, the
Process Counter and the Totalizing Counter are adjusted. When displaying
the Process or Total Counts, the processor takes the raw count (actual number
of count edges that have been entered) and multiplies it by the Scale Factor
and Scale Multiplier and the results are displayed. The Batch Count register,
which is adjusted each time a batch has been completed is displayed directly.
Both the Process Counter and Batch Counter have six Reset Action modes
associated with them. Both of them can be independently configured to
operate in Reset to Zero (up-count) or Reset to Preset (down-count) modes,
and in manual or auto reset modes.
The Process Counter displays the value of display units in the current Batch
cycle. The Preset 2 Value of the Process Counter determines the number of
display units per batch cycle. When the Process Counter reaches Preset 2
(up-count modes) or zero (down-count modes), Output 2, and Relay 2 will
activate and the Batch count will be adjusted by one. The Batch
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