CG1-RADIO
CompactPCI GPS Receiver
Universal Time and Navigation Data from Global Positioning System
Both the global time (UTC) and the
geographical position are provided by the
CompactPCI®
based GPS receiver board
CG1-RADIO, manufactured by EKF.
Most industrial computer systems need
synchronization to a precise time standard.
A solution to this problem would be any
radio controlled clock. Unfortunately, most
countries have their own local transmitter
standards (if any). Hence, for universal use
(e.g. if systems are mobile or destined for
export), a GPS based clock is the best
choice.
The Global Positioning
System provides the
Universal Time
(Coordinated) and - of
course - position data. Most useful for
mobile applications, also country specific
program versions could be executed
automatically. A CG1-RADIO equipped
system can signal its current position to a
remote computer.
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The CG1-RADIO module is housed on a
single size Eurocard (3U). The board is
provided with a high performance
12 parallel-channel receiver engine
continuously tracking all satellites in view,
thus providing accurate positioning and time
data. The receiver is compatible with passive
or active antennas and supports the
NMEA-0183 data protocol.
Direct, differential RTCM SC-104 data
capability dramatically improves the
positioning accuracy. For that, the CG1-RADIO is equipped
with a serial port for
communication with an external DGPS
receiver.
From the hosts view, the enclosed drivers
reduce the CG1-RADIO board to one or two
common serial ports, e.g. COM3/4.
Therefore most of the programs based on the NMEA-0183 data
protocol can be executed
without modification.
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The highly integrated digital GPS receiver
uses the Zodiac chip set
(Rockwell/Conexant) and is accommodated
on a miniature daughter board as an
exchangeable sub-assembly. The 12-channel
architecture provides rapid Time-To-First-Fix (TTFF) under all startup
conditions. The receiver decodes and
processes signals from all visible GPS
satellites, thereby producing a highly
accurate and robust navigation solution.
The external GPS antenna connects to the
front panel mounted SMB style jack and
must have reasonable visibility of the sky.
For best performance, use an active
antenna, especially for a cable length of 3m
and above.
Due to Selective Availability (SA) the GPS
navigation accuracy is limited to 100m for
civil use. The CG1-RADIO however as an
option allows to read in an external
differential signal (DGPS) in order to reduce
the positioning error to 3-5m. For this, the
CG1 is provided with a 9-pin D-SUB
connector (front panel) serial interface port.
Incoming DGPS data must conform to the
international RTCM SC-104 protocol. The
type of the external DGPS receiver depends
on the location. In Germany e.g. there is a
choice between the LW ALF transmitter
(Mainflingen, Deutsche Telekom) or the
RASANT FM RDS System (ARD).
Equipped with the powerful embedded
processor i960RP(D), the board profits from
the built-in PCI bridge as interface to the
CompactPCI®
system bus. For typical
applications, the EKF software drivers let the
CPCI system host view the CG1-RADIO
module as 16C550 UART based dual serial
adapter card (dual COM port).
Available by download, the EKF utility WinGPS
displays the GPS data and allows for synchronization
of the system clock to the UTC.
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The first serial port of the CG1-RADIO is for
on-board use only. It serves as a
communications interface to the GPS
receiver. Commands and data can be sent
to and received from the GPS daughter
board according to the NMEA-0183
standard protocol. The moderate
transmission rate of 4800bps cares for low
interrupt load of the system host.
The second serial port is intended either as
external DGPS interface (read only), or as a
general purpose RS-232E communications
channel. The wiring of the front panel
mounted 9-pin male D-SUB connector SP2
is identical to desktop PC COM ports. When
receiving differential DGPS data at 9600bps
according to the RTCM SC-104 standard,
the GPS daughter module uses this
information for its internal calculations to
sharpen the positioning data. The second
serial interface is also directly readable by
the system host. Programs as LabMon
(Rockwell/Conexant) need DGPS data in
parallel to the GPS receiver for presentation.
If the DGPS data capability of the CG1-RADIO is
not used, then the serial port SP2
is available for general purpose I/O
applications.
The EKF drivers treat the CG1-RADIO
module as 16C550 compatible COM ports.
While the drivers allow arbitrary names e.g.
COM11, practically there exist limitations in
most systems. Typically, COM1 and COM2
are reserved names for the host CPU's serial
interfaces. On the other hand, most GPS
and communications applications will
support COM1..4 only. Therefore COM3 is
recommended to control the GPS NMEA
port (first serial interface of the
CG1-RADIO), and COM4 to be used as
DGPS RTCM receiver (second serial port,
SP2).
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CG1-RADIO - Block Diagram
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There are many commercial GPS application
programs available, often allowing
cartographical visualization. In addition, the
Internet is full of GPS shareware tools. The
common basis of most applications is the
NMEA-0183 protocol, so that they should be
usable with the CG1-RADIO without any
modification.
Developers might prefer to sample and
compute GPS data locally on the CG1 board.
This can be achieved by the local i960 processor.
Program and
data can be stored in a generous amount of
local memory (4MB DRAM and 4MB Flash
EEPROM). As a development tool, EKF
provides the resident monitor/debugger
MON960, which allows stand-alone
operation and download of programs via
CPCI bus or serial interface SP2. Furthermore
EKF can offer turn key ready application
programming support.
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The CG1-RADIO module lends full GPS
functionality to any industrial
CompactPCI®
system. Beginning with applications
needing absolute time stamps or
isochronous control of tasks, up to
programs requiring three-dimensional
navigation, the CG1-RADIO board is the
perfect and affordable choice wherever
GPS can solve a problem.
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CG1-RADIO - Component Assembly
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Technical Specifications |
Printed Circuit Board
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Dimensions
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3U Eurocard (100x160mm), front panel width 20.3mm (4HP), mechanics constructed with
respect to EMC requirements, ejector lever
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CPU
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Microprocessor
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Intel i960RP/RD, 3.3V, 33/66MHz, clocked by system bus (local
oscillator provided when operated as stand-alone)
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Memory
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4MBytes FPM/EDO DRAM, 32-bit, 4MBytes FLASH ROM (SMT)
28F160S5 (Intel, Sharp), 32-bit
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Utilities
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Watchdog and 5V/3.3V voltage-supervisor MAX705, serial
EEPROM 4KByte I2C, optional: ACCESS.bus interface
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Firmware
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Mon960 Monitor/Debugger
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Serial Interface
SP1 (internally)
and
SP2 (externally and internally)
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Protocol
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Asynchronous, serial protocol: 1 startbit; 7 or 8 databits; 1 or 2
stopbits; optional even/odd parity; standard bitrates up to 115,2
kbps, default parameters for GPS operation SP1=4800Baud (GPS
NMEA-0183), SP2=9600Baud (DGPS RTCM SC-104)
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Serial Interface Controller
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2 x 16C550 asynchronous communication element, e.g. Texas
Instruments TL16C550C or equivalent
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Physical Interface SP2
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RS-232E/V.28, PC compatible D-SUB connector male 9-pin, to be used
either as DGPS input or as universal serial COM port, ESD protection
10kV, pin 9 configurable either as RS-232 RI input or +12V power
supply output to external DGPS receiver (PolySwitch resettable fuse
100mA)
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Drivers
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Serial drivers (COM port emulation) available for Windows 2000 and
Windows NT4.0, others forthcoming
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GPS
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Receiver Module
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Exchangeable modular 12-channel receiver, chip set Conexant
(Rockwell) Zodiac, SMB jack for 1575,42MHz (L1 Band) GPS antenna
active or passive, RF signal level at 130dBW ... -163dBW, antenna
supply 0V, +5V, +12V selectable with jumper JANT (PolySwitch
resettable fuse 100mA)
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Data Retention
Warmstart
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Keep-Alive power condition for enhanced TTFF upon power-up (Time
To First Fix), SRAM and RTC data non-volatile buffered by Lithium cell
190mAh (>4500h)
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Software
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NMEA protocol based application programs
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CompactPCI® Bus
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Connector J1
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32-Bit, 33MHz (133MB/s),
DMA Bus Master,
5V Interface
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Power Supply
Requirements
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Connector J1
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+5V ± 0.5A max.
+3.3V ±0.3V 0.7A (i960RP) 0.9A (i960RD) max.
+12V ±5% 0.1A max.
-12V ±5% 0.1A max.
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Temperature
Humidity
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Commercial Grade Version
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operating temperature 0-70°C
humidity 5-90% non condensing
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technical specifications are subject to change wihout further notice
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EKF WinGPS
A Windows 2000 Tool to Display GPS Data and Synchronize System Time
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Jumper Configuration Fields |
JANT
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Antenna passive, antenna active +5V, antenna active +12V
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JBAT
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Lithium battery for data retention of GPS module's RTC and SRAM
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JCLK
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CPU clock derived locally or from CPCI bus
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JCNF
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CPU behaviour after reset, effects of CPCI reset on CG1-RADIO
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JWZ
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Serial port SP2 D-SUB pin 9, configured either as RS-232 RI input or +12V
output as power supply to external WZ DGPS receiver
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External Connectors (Front Panel) |
ANT
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RF input 1575,42MHz (L1 band), GPS antenna active or passive, input
signal level at -130dBW ... -163dBW, SMB jack, power supply voltages
selectable 0V, +5V, +12V (jumper JANT), PolySwitch resettable fuse 100mA
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SP2
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RS-232E D-SUB 9 male connector, can be used either as unversal serial
COM-port (standard bitrates up to max. 115,2 kBaud), or as DGPS input
(according to RTCM SC-104 protocol, 9600bps, 8bit, 1 startbit, 1 stopbit, no
parity)
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Internal Headers (Optional) |
CJTAG
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JTAG testport
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ISPCON
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ispGAL programming port
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JACCBUS
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I2C-Bus expansion interface
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JUTC
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TTL time mark pulse 1Hz and 10kHz, synchronized to the UTC Universal
Time (Coordinated)
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SP2 serial port (DGPS input)
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Ordering Information |
Alias
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Ordering Number
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Short Description
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RADIO
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CG1-1-RADIO
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3U CompactPCI hostadapter, 12-channel GPS
receiver subsystem with i960RP CPU/bridge,
4MB Flash, 4MB DRAM, MON960
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CR9-1-ADAPT
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Mechanical kit, expands front panel from 3 U to 6U
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940.80.20125.1
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GPS antenna, active +5V, SMB connector, 5m
cable length
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940.80.90100.1
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External DGPS LW receiver box, including ALF
license (Accurate Positioning by Low
Frequency, transmitter Mainflingen/Frankfurt,
receiver radius about 650km)
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