Control Module Design

1
Control Module Design

• Ryan Miller
• STARLight Electrical Engineer
• [phone]
• rpmiller_at_umich.edu

2
Overview

• Control Module Requirements
• Digital Signal Processing
• Data Formatting and Rates
• Hardware Overview
• Power Summary
• Software Overview
• Schedule

3
Control Module Requirements

• Provide overall control for the STARLight
  instrument
• Allow modification of system parameters
• ADC Gain/Offset
• Sample Clock Delay
• Integration Period
• Provide signal processing of sensor data
• Inphase and Quadrature correlations for all 10
  channels
• Autocorrelations for all 10 channels
• Format and store processed data in non-volatile
  storage
• Format and store housekeeping data with sensor
  data
• Provide GSE interface for data download and
  real-time display and control

4
System Block Diagram
5
Correlation

• Auto-correlations for each channel (10)
• Cross-correlations for every pair
  (IxI,IxQ,QxI,QxQ)
• 10 pairs of I and Q signals (20 signals)
• 190 correlations
• Selectable integration period (1 to 2 seconds,
  nominal)
• Correlator Output (one second integration)
• 200 channels/second 30 bits per channel 6000
  bits/sec

6
Data Storage Requirements

• Total Data Rate 11,000 bits/sec
• Sensor 6000 bps
• Housekeeping 3000 bps
• Other 2000 bps
• Mission Time is approximately 3 hours
• Total on-board storage needed
• 11000 bits/sec 3 hours 3600 sec/hour 15
  Megabytes

7
Control Module Electronics Block Diagram
8
Correlator Block Diagram
9
Control Module Hardware

• PC/104 based system
• Control Computer
• Commercial PC/104 Pentium Single Board Computer
• I/O
• Commercial PC/104 Data Acquisition Board
• IR Profiler thermocouple interface
• Power supply voltage monitoring
• Correlator
• Custom PC/104 style board with interface to the
  Control Computer
• Custom interfaces to the Sensor Module
• Pilot interface electronics
• Power Conditioning and Supplies
• Converts aircraft power to required system
  voltages

10
PC-104 Mechanical Info
11
PC-104 Mechanical Info (cont.)
12
EBC-TXPlus Single Board Computer
5.75

• Intel Pentium 166MMX, AMD-K6
• 32 to 256MB of system SDRAM supported in 168-pin
  DIMM
• Socket for up to 288MB bootable DiskOnChip
• PC-compatible uses Intel 430TX chip set
• Ethernet controller using Intel 82559ER
• 4 RS232 serial ports with FIFO, COM1 COM2 with
  optional RS-422/485/J1708 support
• 48 bi-directional TTL digital I/O lines with 24
  capable of event sense interrupt generation
• PC/104 and PC/104-Plus expansion connectors
• Three 16-bit counter timers
• Extended Operating Temperature Available for 166
  MHz board from -40oC to 85oC
• 5 volt only operation
• Real Time Clock, WDT and power fail reset

8.0
13
PCM-518 Sensor Interface Module

• Supports thermocouples, RTDs, strain gauges,
  voltage inputs, 4-20 mA current loops, and
  thermistors
• 8 Channels of 16-bit A/D resolution
• Each channel software programmable for sensor
  type and gain
• Onboard processor unburdens PC/104 system CPU by
  performing control, linearization, and conversion
  to engineering units.
• True four-wire circuits for resistive sensors
• Pulsed excitation source reduces self-heating in
  resistive sensors
• Totally electronic calibration - no trimpots to
  adjust
• Optional ADP-7409TC field termination board
• Screw terminals for easy wiring
• Supplied with 8 removable terminal blocks
• Integral cold junction temperature sensor for
  thermocouples

3.6
3.8
14
Power Summary
15
Software Overview

• Developed using QNX Real-time Operating System
• Provides real-time operation, interrupt handling,
  TCP/IP networking
• Provides overall system control
• Sensor parameter setting
• Data collection
• Data formatting and storage
• Provides thermal system control
• PID Loops using sensor temperature measurements,
  10 channels
• Provides GSE interface
• 100 BaseT TCP/IP
• Realtime data transmission
• Stored data collection
• Interactive control

16
Software Structure
17
Schedule