JanisULT's second-generation Gas Handling System (GHS2) contains JanisULT Automated Control Box (JACoB), JanisULT Mixture Enclosure (JAMiE) and Pumping Station (PS). It can be used for both the JDry series cryogen free and JDR series "wet" dilution refrigerator systems. (The model 100 series does not require a Roots Pumping Stations.)
JanisULT Automated Control Box
JACoB is a totally new automated control unit for the next generation JanisULT dilution refrigerator Gas Handling Systems (GHS2). It includes the following features:
- All control electronics, including the highly reliable National Instruments real-time operating system controller (cRIO), are located inside a 19” rack enclosure;
- A single manifold incorporates miniature Pfeiffer solenoid valves as well as pressure and flow sensors, and is easily removable and serviceable;
- A color touch-panel computer functions as human machine interface (HMI) and contains the flow diagram with all valves, pumps, compressor, and gauges. The HMI is accessible via touch-fields as well as via mouse/key-board – no need for mechanical knobs anymore!
- The HMI WindowsTM XP computer communicates with the controller via internal LAN, and can be accessed (or located) remotely via the Internet;
- JACoB communicates via GPIB with an AC resistance bridge and optional Agilent 4263B LCR meter for temperature measurements;
- A built-in UPS allows up to one hour of full system functionality in the event of a power loss;
- The system provides full control over vacuum pumps and pulse tube cryocooler compressor operation, including status check and interlocks;
- Data logging to internal or external hard drive is provided, including all temperatures, pressures and flow rates;
- JACoB does not require an individual LabVIEW license.
The JACoB provides automated dilution refrigerator (DR) control based on a standard 19” enclosure, and incorporates a manifold of Pfeiffer miniature solenoid valves, three Pfeiffer wide range pressure sensors, MKS flow meter and control electronic.
A powerful UPS unit allows more than one hour of battery-backed operation with all the electronics energized, including two computers and all valves.
The valve control electronics, pressure and flow sensor display, and pump control are based on rugged National Instruments cRIO platform. The real time operating system cRIO controller and I/O modules are housed inside a 4 slot cRIO chassis within the control box. Three cRIO plug-in modules control the valves, pumps and compressor, and monitor the various sensors.
A NI touch-panel computer (PPC2115 with Windows XP) is located on the front panel of the JACoB. The touch panel (TP) contains a mixture flow diagram with all valves, pumps, pulse tube (PT) compressor and gauges clearly displayed. The valves are opened or closed, and pumps and compressor operated by depressing valve indicators (fields) on the flow diagram. The TP also serves as a gauge indicator, showing pressure and flow in real time. The TP communicates with the cRIO controller via internal LAN (Ethernet). The TP can be optionally placed in a remote location (control room) or a TP client program can be operated from any other Windows computer and connected to JACoB via built-in Ethernet port.
All JACoB programming is done in LabVIEW, including cRIO and touch-panel, but there is no need for a separate LabVIEW license – all programs are installed as WindowsTM executables. An independent LabVIEW executable program is installed on the touch-panel computer and operates the DR temperature measurement and control system via GPIB interface. This program utilizes a LSCI model 370 temperature controller for resistive temperature sensors, and optional Agilent 4263B LCR meter for measuring CMN/FPD temperature measurement devices. This software plots and logs all temperature, pressure and flow data from JACoB in real time. It also performs PID control over the DR still and mixing chamber heaters.
JAMiE is based on a similar 19” enclosure with locking wheels and contains one or two aluminum mixture dumps inside. Optionally, the JAMiE enclosure can be located under JACoB acting as its base. Two stainless steel flex-hoses connect JACoB and JAMiE. The system is charged with optimized 3He-4He mixture for each particular DR model.