CG2-SHANTY

The CG2-SHANTY is a CompactPCI® based GPS receiver board, allowing to determine the geographic position (including speed and velocity), and to synchronize a system with the global time (UTC).

Often industrial computer systems need synchronization to a precise time standard. A solution to this problem would be any radio controlled clock. Unfortunately, most regions have their own local transmitter standards. Hence, for universal use (e.g. if systems are mobile or destined for export), a GPS based clock is preferable.
The CG2-SHANTY incorporates a highly integrated digital GPS receiver, which uses the SiRFstarII chipset and is accommodated on a miniature daughter board as an exchangeable mezzanine 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. In a typical situation, a horizontal accuracy better than 3m can be achieved. 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 (+5V or +3.3V selectable power), in particular for a cable length of 3m and beyond.

Under certain conditions, differential RTCM SC-104 data capability can further enhance the positioning accuracy. For that, the CG2-SHANTY is equipped with an additional serial port for communication with an external DGPS (Differential GPS) receiver.

With respect to the CompactPCI bus, the CG2-SHANTY appears as a quad serial adapter card, based on 16C550 compatible PCI UARTs (which are also known as COM-ports in a typical PC). The first serial port of the CG2-SHANTY is for on-board use only. It serves as the 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. When operated in NMEA ASCII mode, the moderate transmission rate of 4800bps cares for low interrupt load of the system host. As an option, the SiRF binary raw data protocol allows much higher throughput. The CG2-SHANTY 3U Eurocard is provided with a high performance receiver engine continuously tracking all satellites in view for a time accuracy better than 1us and horizontal accuracy better than 3m. The receiver is compatible with passive or active antennas and supports the NMEA-0183 data protocol, thus allowing nearly any GPS application program to be used with it.

The CG2-SHANTY module lends full GPS functionality to any CompactPCI® system. If GPS technology can solve a problem, this board is a reliable and economic choice.
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 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 can process DGPS data in parallel to the GPS receiver data for presentation.

The remaining two serial ports are currently not in use. However, the CG2-SHANTY can be optionally equipped with connectors suitable for attachment of external PHY transceiver modules (EKF CU-series, e.g. CU7-RS485).

The CG2-SHANTY provides a pulse output (1pps) with better than 1us timing accuracy, which can be used to generate interrupts in order to synchronize processes.

Available by download, the EKF utility WinGPS displays the GPS data and allows to synchronize the system clock with the UTC (Universal Time Coordinated). 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 CG2-SHANTY without any modification. Furthermore, there are various commercial GPS application programs available, mostly allowing comfortable cartographical visualization.