University of Bergen public domain software: SEISLOG Linux, data-acquisition system for standard PC and embedded lowcost, low-power solutions Terje Utheim Department of Earth Science, University of Bergen, Norway SEISLOG Linux embedded Embedded ? The word “embedded” in the case of SEISLOG Linux can be defined as: The computer used is a single-board micro-computer The computer will normally not have keyboard, monitor or mass storage such as standard hard disks connected The operating system is pre-installed in flash memory and is a stripped version of standard distributions of Linux to save memory space. The application software is also stored in flash memory Communication with the computer is done through a console serial port or through Ethernet with a terminal emulator. Low-cost Low-power 3 different single-board micro-computers have been tested. The boards normally have connectors for: 1-3RS-232 serial ports 1Ethernet port 1-2USB ports The CPU speed range from MHz Power consumption at 5V: around 300mA The price range from $100-$200 Embedded SEISLOG Linux Software All SEISLOG routines are written in C Software identical for Desktop PC, Laptop and embedded Utilities for monitoring and graphics written as clients communicating with SEISLOG server over sockets. Ringbuffer files and event files are written in MiniSeed format SEISAN S-files written in SEISAN database structure Waveform data written in SEISAN database structure Server function emulates LISS server (transmission of 512 byte miniseed blocks over Internet Design and Data-flow SEISLOG is built around the concept of POSIX threads. Each thread serves different purposes like reading data from a digitizer, writing data to memory ring-buffers, detecting events and recording of events. FTP/Telnet can be used to retrieve data from SEISLOG whether its from a desktop PC or an embedded system. A server module that communicate over sockets, takes care of communication with utility clients like monitoring and plotting of signals. A server function that emulates the LISS server will send out miniseed data buffers on request. The data buffers received can be plotted with the utility LISSPLOT in “near-real-time”. LISSPLOT can also be used to plot data from any station in the GSN network. The data buffers from the server can also be used as input to Earthworm or SeisComp The SEISLOG program in various versions has been around for more than 15 years. Currently SEISLOG runs on the platforms Linux, Windows, PocketPC(CE) and QNX (discontinued). The Linux version runs on different Linux embedded versions on different hardware architectures. The Linux and Windows versions optionally record data directly into a SEISAN data base in miniseed format. All SEISAN tools can then be used directly on the recorded data, including automatic processing. A built-in server-function is also sending out data buffers in LISS format. These data buffers can be requested for local or remote plotting. Data from the server can also be requested, locally or remotely, as input to Earthworm or SeisComp/SeedLink. The SEISLOG Linux version for standard PC now also supports different low-cost, low-power boards that can be used in the design of portable recorders or permanent seismic stations. Common for these systems is that the operating system Linux, is normally pre-installed (embedded) in flash memory. Data can be recorded on USB pens up to 4 Gb. Data can be retrieved manually by changing the USB stick or through local or remote Ethernet-Internet connection if available. Hard disks are normally not connected to keep power consumption at a low level. The source distribution for the SEISLOG embedded is identical as for standard PCs, but must be compiled with a cross-compiler for the specific board. TS MHz 32 Mb SDRAM 32 Mb Flash Ethernet 3 x Serial ports 2 x USB Options: Serial lines PC104 Linux and SEISLOG embedded DigitizerUSB pen Ethernet SEISLOG Shared Memory Data-structure Driver Digitizer SRV LISS Server 512 byte blocks MiniSEED Steim 1 Compr. SeisComp Acquisition Plugin LISS SeedLink EarthData RD3 SADC24 MiniSEED blocks can be requested on localhost or remotely via Internet. The LISS protocol is one-way only. Earthworm On SEISLOG Windows and SEISLOG Linux, SEISAN can be installed, and data can be recorded directly into the SEISAN data base for local processing. LISSPLOT SEISLOG Linux design LISSPLOT, Limon Verde, Chile,GSN Monitoring remote or local SEISLOG LISSPLOT, SEISLOG test station Configuration and applications There are several single-board computers on the market in which SEISLOG can be installed. Three different systems have been tested and they are all in the same price range. It is important to notice that the source distribution of SEISLOG must be re-compiled with the corresponding cross-compiler for the specific board and transferred to the boards flash file system. The boards comes with a “stripped” version of Linux and one must be aware that some functions will be missing compared to a standard distribution of Linux. On the right are shown three figures of SEISLOG embedded systems: Figure 1 shows an example of a single-board computer. The board has Linux and SEISLOG installed in flash memory. The dimension of the board is 3.8x4.8 inches. Figure 2 shows a complete system from SARA containing: digitizer, sensors, GPS and the TS-7260 integrated with SEISLOG and a 2 Gb USB pen mounted for data recording. The system can be installed in the field as an automatic station for days/weeks depending on the availability of power (2.5W). Figure 3 shows a test system with the TS-7260 connected to an Earth Data digitizer. This system is connected to the Internet and can be operated locally or remotely. Data can be downloaded with FTP. Single-board TS-7260 TS-7260 with SEISLOG integrated in box with a/d, GPS and sensors Test system: TS EarthData Figure 1 Figure 2 Figure 3