|
|
|
|
| The Genesis Control System is the culmination of thirty years of Scientific
Instrument's involvement in the cryogenic temperature controller business. The Model PC
2001 is the most unique Cryogenic Temperature Controller ever offered. The PC 2001's
primary innovation involves the use of a personal computer to replace the instrument's
front panel, for those who primarily use the temperature controller under computer
control. |
 |
|
|
|
| Why spend the additional monies for a front panel display if you intend to use your
temperature controller with a personal computer? A Virtual Instrument running under the
Windows® operating system is created on the personal computer. This program
can be run as a stand-alone application under Windows® and provides the user
with complete and easy access to all the features of the controller via a user-friendly
graphics interface. A simple LCD display and a dead front LED bar graph are provided on
the controller which allows constant monitoring of the primary temperature and heater
power. |
 |
|
|
|
The PC 2001 comes standard with four channels of Silicon Diode signal
conditioning. Connectors are provided on the rear panel for additional plug-in signal
conditioning cards to accommodate the following types of sensors:
- RTD's
- Thermocouples
- Optional
|
|
| The four channel capacity of each controller can accommodate any mix of the sensors
listed above and may be changed in the field. Various types of sensor excitation are used
depending on the sensor type. All signal conditioning circuitry is included on the card
necessary to provide an output voltage of 0-5 volts over the specified temperature range. |
|
| Some of the functions provided are gain, filtering, and output voltage averaging. An
EEPROM is included on the card which holds calibration data unique to each sensor. The
output from each card is digitized by a 24-bit A/D converter inside the instrument. This
method allows signal conditioning cards to be designed for almost any kind of sensor, thus
minimizing obsolescence due to new sensor technology. |
|
|
|
| The Heater Power Supply has been completely redesigned for the PC 2001
controllers. The new power supply is a programmable DC Current Source Output that
incorporates open and short circuit protection to the 50 volt supply in the event that the
power transistor experiences a collector-emitter short, and short circuit protection to
ground in the event that the current is diverted away from the heater coil. Active current
limiting has also been incorporated into the fail-safe protection circuitry. |
|
|
|
| Perhaps the most advanced technological benefit of the Genesis TCS is it's use of
"Intelligent Adaptive Autotuning." At the present time, due to the "Patent
Pending" status of this feature, no additional information may be provided. |
|
|
|
 The PC 2001 may be a virtual
instrument, or simply the operator's front panel, and is constructed on a personal
computer as an application running under Windows® operating system. All of the
features of the temperature controller may be operated from this screen by means of a
pointing device such as a mouse or the standard computer keyboard. By utilizing the entire
screen, a very user-friendly interface is possible and the data may be displayed in an
easily understood format. The temperature controller may be operated in all modes, data
graphed in real time, and stored to disk if desired. Calibration curves for sensors may be
viewed, edited, and downloaded from disk into the controller. Additionally, temperature
versus time profiles may be created, graphed for verification and downloaded for
execution.
Virtual instrumentation utilizes the current availability of PC's as the operator
interface without duplication of costly displays and controls. Increasing capabilities of
modern instruments requires a more complex operator interface to be able to use the
capability of the instrument. Using graphical interface of Windows® gives the
capability of guiding the user through potentially difficult and confusing operations with
relative ease and very little if any reference to a written manual. potential mistakes in
instrument setup and data entry are minimized. The built-in flexibility provides the
capability to respond to changing requirements in the market place and the addition of
features without costly hardware changes. These benefits are passed on to the customer at
costs lower than conventional techniques would allow. |
|
|
| A driver for National Instruments LabVIEW® is provided for customers who
are using that programming environment. Windows® software, along with the
LabVIEW® driver, is included in the base price of the instrument. All features
of the Genesis controller are supported, thus eliminating the need for the customer to
write the virtual instrument driver. Communications may be by either RS-232, RS-485 or the
GPIB interface. The source code is provided so that the customer can make modifications to
meet special needs if desired. |
|
|
- Number of channels: Four (4) channels standard
- Multiple sensor types may be used on each channel via use of plug-in signal conditioning
cards
- Internal 24 bit resolution for all sensors
- Silicon Diode standard on all four channels. Separate signal conditioning cards for
different sensor types without instrument modification
- Sensor excitation: 10 microamperes for Silicon Diode, variable for other sensor types on
signal conditioning cards
- Four-leaded sensor measurement
- Two A/D converters. One is dedicated to the control sensor and one is used to scan the
other three channels. Control sensor update time is less than 60 ms
|
|
|
- Display resolution: User selectable from 1K to 0.001K on all sensors in selected
temperature ranges
- Display units: Kelvin, Celsius, Fahrenheit, Volts, Millivolts and Ohms
- Continuous display of heater output via bar graph display.
- Set point resolution: 0.001K
|
|
|
- Heater output: 50 watt maximum (50 volts @ 1 amp), 16 bit resolution.
Output is current regulated with short circuit protection.
- Programmable maximum current: 1.0, 0.1, 0.01, and 0.001 amps (x 2 for 100 watt option)
- Programmable current output on heater circuit for manual control
- Analog output (16 bit) programmable by customer to one of three functions:
- Analog output of temperature
- Deviation from set point
- Second heater control: 0 - 10 Volts @ 0.1 Amps
|
|
|
- Intelligent Adaptive Nonlinear Control for optimum heater power control
- Two computer interfaces are standard, RS-232 and GPIB (IEEE-448). All controller
functions and data are available via both interfaces
- GPIB complies with IEEE-488.2 Standard
- RS-232 interface supports 300 - 38,400 Baud
- RS-485 (RJ-11) interface
- Universal Power Supply: (90 to 250 volts, 50 - 60 Hz)
- Time versus temperature ramping: 100 time versus temperature pairs
- Single and multiple point calibration capability
- User definable voltage / temperature curves for special applications
- Filtering: Customer selectable
- Two mechanical relays with programmable set points on any specific sensor
- Data logging capability for stand alone applications
- LabVIEW® driver available
LabVIEW® is a trademark of National Instruments.
Specifications are subject to change |
|