The automated control and data acquisition system UNICON-sb-I / O-3 is intended for automated control of the process of liquid-phase epitaxy of semiconductor layers on gallium arsenide substrates (and other materials with appropriate software). The system records the temperature at the specified points of the vacuum chamber and controls the heating and cooling of the multi-loop resistive or induction heater according to the temperature profile. The values of the profile curves, its graph, temperature in different parts of the vacuum chamber and the process flow are displayed on the screen of the human-machine interface of the system. A full log of system parameters is maintained. Data exchange between system nodes is carried out via the internal bus or via Ethernet (external modules), power circuits are controlled directly via digital and analog I / O lines, or via RS-485 (RS-232) interface.
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1. Short description
The control system and data collection UNICON-sb-I / O-3 (hereinafter - the system) is mounted in the housing with the peripheral I / O interfaces, nourishing and protective circuits. Provided uninterrupted power supply and short-circuit protection. The output stages are galvanically isolated control, and remote I / O modules are intrinsically safe barriers for protection when working in potentially explosive (hydrogen, methane, etc.) laboratory or production environment in the management of high-current load.
2. Main features and technical specifications of UNICON-sb-I / O-3
- Join the temperature values at the three points of the vacuum chamber with an accuracy of ± ° C 0,1 1 sampling frequency of once per second.
- Control of two- and / or three-circuit (by agreement) resistive heater with the accuracy of temperature maintenance ± 0,2 ° С.
- Implementation of heating the sample GaAs substrate by the temperature profile (graphics - the temperature-time).
- Precision control of the substrate cooling process temperature profile (graphics-time temperature).
3. The basic structure of the system
a. The system and hardware specifications
| Embedded system with subsystems Real-Time, FPGA and the input-output subsystem | Couplemeter |
| Switching C-Series Expansion I / O Modules | Yes, up to 2х |
| Interface 10 / 100 BASE-T Ethernet | 1 |
| Interface RS-232 | 1 |
| CAN interface | 1 |
| Interface RS-485 | 1 |
| Supply voltage | from the 9 30 to V DC |
Features subsystem Real-Time и FPGA |
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| CPU frequency | 400 MHz |
| Nonvolatile memory | 256 MB |
| Amount of RAM | 128 MB |
| Nominal frequency of FPGA (power key management) | to 40 MHz |
Characteristics IO subsystem |
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| The ability to connect the following thermocouples | J, K, T, E, R, S, B, N |
| Number of channels for connection of thermocouples | 8 |
| Sampling frequency of synchronized analog inputs | to 10 Hz (up to 100 when negotiating) |
| Bit ADC | 16 bit |
| ADC dynamic range | 110 dB |
| Measurement error | 0,1% |
| Number of analog output channels | 4 |
| Output Voltage Range | In 0..10, 0..5 V, ± 5V, ± In 10 |
| Ranges of output current change | 0..20mA, 4..20 mA |
| Bit DAC | 14 bit |
4. The system software and software functions of each part
Software UNICON-sb-3. Specialized software for the heating-cooling process for the liquid-phase epitaxy.
a. Functions ON FPGA subsystem
- Measurement and coordination signals thermocouples;
- Filtering thermocouple signals;
- PID control module operation;
- Formation of a control signal by a resistive heater according to the temperature profile and the PID control law;
- Output signals for controlling a resistive heater;
- Handling emergencies, emergency stop process.
b. Functions of the software subsystems Real-Time
- Communication with FPGA subsystem through DMA channels and FIFO;
- Data exchange with the host system via Ethernet, CAN and Shared Variable, TCP / IP, CANopen, Modbus;
- Formation of the temperature profile on the basis of data from the host system;
- Deterministic time performance of the temperature profile with the ability to pause, stop, continue and an emergency stop process;
- Performing heater control based on data from thermocouples for liquid phase epitaxy process.
c. Host software features
- The interface with the operator.
- Data exchange with the Real-Time subsystem via Ethernet, CAN interfaces and Shared Variable, TCP / IP, CANopen, Modbus protocols.
- Save the experiment data in the form of log files.
- Saving the configuration and parameters of the heating profile of the experiment to configuration files.
- Download configuration files to re-set experiment parameters.
- The output of diagnostic messages on the state of the system operator.
Components, form factor, conditions of delivery and terms of commissioning works to be agreed. Price is available on request after approval.