A software set for environment monitoring networks

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1 A software set for environment monitoring networks G. Zappalà IAMC, Istituto per l Ambiente Marino Costiero, Section of Messina, Consiglio Nazionale delle Ricerche, Italy Abstract This paper describes a set of software programs expressly designed and coded to be used in a buoy-based environmental monitoring network. The network consists of seven remote acquisition stations mounted on coastal buoys in Sicilia and Apulia and a control base located in Messina. The peculiarity of the software and of the transmission system (GSM) enables one to locate the base station wherever preferred, without the need for coastal repeaters. The data acquisition system is based on PC104 (IEEE696) standard boards, hosting a ROMDOS operating system under which the control program runs. The first program runs on the remote stations and manages all the data acquisition and transmission operations; a sequence manager starts every hour a macro-command sequence that can be different for each time and is remotely reprogrammable; new releases of the software and of the sequences are uploadable to the station without suspending its normal activity. The macro-commands enable one to manage the data acquisition and transmission, the station hardware and the measuring instruments. The data transmission and the remote station management are performed via GSM, SMS and . The second program, running in the Windows environment, is a Control Terminal with embedded utilities to help users in the management of the remote stations. Different software perform the data validation, selection, display and storage in an Oracle database. Further experiments are in progress to implement GPRS data transmission. Keywords: marine monitoring, buoys, data transmission, GSM. 1 Introduction In recent years, surveys of water quality and meteorological parameters, both at medium and long term scales, have been made possible by the availability of

2 4 different kinds of coastal and offshore buoys and platforms, like those described, among the others, by Grisard [1], Griffiths et al [2], Paul [3], Seim et al [4], Pinardi et al [5]. New devices and systems for marine monitoring have been designed in the framework of the SAM (Sistemi Avanzati di Monitoraggio Advanced Monitoring Systems) and PI-CNR (Potenziamento Infrastrutture Infrastructure Increase), two programmes funded by the Italian Ministry for University and Research (MIUR), in the framework of CLUSTER 10. One of the most significant results has been a network of coastal monitoring buoys, reported by Zappalà et al [6]. The systems developed constitute a further improvement and application of the know-how acquired in past programmes, described in Crisafi et al [7], Zappalà et al [8,9,10], so making the PI-CNR project an opportunity not only to buy expensive instruments, but also to develop advanced technology devices, to be used in monitoring activities. The monitoring systems can perform meteorological observations and measurements of physical, chemical and physico-chemical parameters characterizing sea water state and quality, current speed and direction; the measuring devices range from static sensors (e.g. Pt100 for temperature) to colorimetric analyzers for nutrients; a water sampler, taking samples for further laboratory determinations, may also be included in the systems to complete the series of measurable parameters. Water measurements can be carried out in situ at fixed depths, on samples pumped from various depths into a measurement chamber on the buoy, or using profiling instruments, each choice presenting different advantages and disadvantages. Power supply and data communication equipments often represent the main design constraints, involving the frequency and kind of measurements and the size of the buoy. The first is usually provided by solar cells that recharge batteries, while the choice of the data transmission system depends on the distance from the shore and on the quantity of data to be transferred. Offshore buoys generally use dedicated HF-VHF-UHF radio links, satellite (INMARSAT, ARGOS ) communication or (seldom) cellular telephony (ETACS, GSM or satellite based); for coastal buoys GSM and GPRS offer a low cost solution, enabling also the use of SMS (short messages) and to transfer data and/or commands. 2 The hardware and software of the systems The software here described was conceived to run in a data acquisition and transmission system hosted on small (8 square metres) coastal buoys, powered by batteries recharged by solar panels and wind generator (fig. 1). The monitoring system comprises the following measuring devices: a meteo station equipped with Theodor Friedrichs sensors for air temperature, wind direction (referenced to the heading of the buoy measured by a Precision Navigation blind compass) and speed, pressure, solar radiation.

3 5 Figure 1: The monitoring buoy near Messina. a system for pumping water samples from 5 depths (Idromar), equipped with IM50 probe measuring water Temperature, Conductivity, Dissolved Oxygen, Turbidity, Fluorescence. 5 SBE 39 T in situ probes at the same sampling depths. an experimental colorimetric Nutrient Probe Analyzer (Systea) sequentially measuring in few minutes ammonia, nitrate, nitrite and orthophosphate by one on-board double-beam solid state colorimeter. a water sampler for microbiological laboratory analysis, able to collect, fix with formalin and store up to eight 250 ml samples. a Nortek Aquadopp 600 Acoustic Doppler Current Profiler (whose performance from a floater is now being tested), measuring current speed and direction in 20 layers equally spaced in depth. More devices can easily be added. 2.1 The data acquisition and transmission system The data acquisition and transmission system, shown in fig. 2, is based on IEEE P996.1 standard boards; it features a 40 MHz 386 CPU, 10 RS-232 ports, an 8 inputs 12 bit ADC, 48 power outputs with connected circuit status feedback, 24 simple power outputs, a dual band GSM modem; the mass storage is supplied by Disk on Chip (DOC) devices. It meets (with some variations) and sometimes exceeds the capabilities of the ARES architecture described by Lessing and Henderson [11].

4 6 Figure 2: The data acquisition and transmission system. The environment is Datalight ROMDOS v. 6, an MS-DOS compatible Operating System. The software was written in Microsoft Professional Compiled BASIC v and Microsoft Macro Assembler v It enables to fully control the platform instruments both in local and remote mode using a special set of macro commands that include also conditional execution of branches; this feature can be very useful in case of partial operativity of the platform due, for instance, to low battery level or failure of some instrument. An embedded sequence manager starts each hour a programmed sequence of macro commands that can be different for each time and is remotely reprogrammable. New releases of the software are uploadable to the instrument without suspending the normal operativity of the system. The macro commands can be combined into sequences using a simple text editor. The syntax of the commands is very easy: every macro command begins with the letter Z, followed by a letter identifying the command and by the variable parameters (if any). Available commands include: System management commands Instrument management commands Conditional branch commands Data transmission commands A commented sequence of macro commands is presented in table 1.

5 7 Table 1: A sample sequence of macro commands. ZZ seqtemp.dat ZZ this is a sample measurement sequence, sequentially reading input from the ZZ five SBE 39 Temperature probes and then transmitting the acquired data ZZ the lines starting with ZZ are comments ZZ switch on T-probes ZI 49 1 ZZ the command ZI xx y switches on (if y=1) or off (if y=0) output n. xx ZZ T-probes power supply comes from output n. 49 ZZ wait 60 seconds ZU 60 ZZ the command ZU xx causes a pause of xx seconds in the elaboration ZZ read probes, starting with the deepest ZZ the command ZT xx causes acquisition from the T-probe on serial input xx ZT 10 ZT 9 ZT 8 ZT 7 ZT 6 ZZ transmit measured data ZE ZZ the ZE command sends the data measured by the five T-probes ZZ switch off T-probes ZI 49 0 ZZ end of measurement sequence An example of use of conditional branch is shown in table 2; it must be noted that the compared value must be measured before performing the test using the proper command. Every measurement command returns 15 values: 10 measurements, the minimum (value n. 11), the maximum (value n. 12), the mean (value n.13), the standard deviation (value n. 14), the number of valid measurements (value n. 15); the conditional branch test may be performed against any of the values. Measured data are transmitted via GSM SMS and to the main data centre, where are automatically inserted into the Data Bank for further validation and integration (see Bergamasco et al [12]). The command-data flow is shown in fig. 3. During inactivity periods, the system enters a low-power sleep mode from which it is wakened up synchronously each hour by the sequence manager or asynchronously by the reception of a modem connection. A watch dog timer automatically resets the system in case of hanging. 2.2 The control terminal The Control Terminal Program was written in Microsoft Visual Basic 6.0 to run in Windows environment.

6 8 Table 2: An example of conditional branch coding. ZZ this sequence shows an example of conditional branch ZA 4 ZZ the ZA 4 command reads the analog inputs Z? > ZZ the Z? xx yy zz o vvvvvv command performs like a IF THEN ZZ the xx is the number of the port from which read the value to be compared ZZ the yy is the number of the channel of the port ZZ the zz is the number of the measure (13 represents the mean value) ZZ the o is the comparison operator ZZ the vvvvvv is the comparison value ZZ the THEN section will be processed if the mean of the values measured on ZZ analog input number 1 is greater than 380 ZZ this is the THEN section Z@ ZZ the Z@ command starts the ELSE section ZZ this is the ELSE section Z& ZZ the Z& command represents the END IF section ZZ end sequence Figure 3: The command-data flow. It basically integrates a Terminal program with three utilities: an application sequence generator, an HEX file generator and a file upload manager. From the main terminal window it is possible to customize and use the terminal program or to activate the specific utilities.

7 The application sequence generator The application sequence generator is a menu-driven utility that generates the sequence files containing the macro commands for buoy mission programming. An example of screen is displayed in fig. 4; the top frame is used to choose the kind of operation to be performed (instrument measurement, device management, program management). Figure 4: The Sequence Generator screen. The example shows the insertion of a conditional branch instruction (similar to the IF..THEN) into the sequence file. This choice opens an intermediate frame, where it is possible to specify the conditions; in this example the condition is based on the raw result of the measurement on the first channel of the A/D converter: if between 154 and 398 the THEN section will be processed, otherwise the program flow will be diverted to the ELSE section. After the complete specification of the condition it is possible to write the generated macro command to the text box displaying the sequence file or to abort the operation The HEX file generator It is possible to transfer files to the data acquisition and transmission system coding them in a specifically designed format, somehow similar to an ascii coded hexadecimal dump, with checksum and transmission order information.

8 10 Although not very fast (it increases the amount of data to be transmitted), this format is a reliable and safe way to encode small amounts of data (e.g. the sequence files generated by the application sequence generator ) The file upload manager This utility was designed to perform automatic uploads of HEX files to the data acquisition and transmission systems in the buoys; it can work in a manual, automatic, or blind mode. The file transfer happens one line at a time, with the first line (numbered 0000) containing the file name and the last line (numbered 9999) signaling the end of file. In blind mode the lines are sequentially sent, at timed intervals, without waiting for any feedback; in manual mode, the user will wait for a feedback from the remote computer, then will choose to press the ENTER key to send next line, or BACKSPACE to resend the most recently transmitted; in automatic mode every need is managed by the program. It is possible to start (or resume) the file transmission at any line number. 3 Discussion The systems here described were developed in 2001 and used in installed buoys since 2002; the original design was upgraded in March 2003, adding more powerful commands in the software and tuning the hardware for the best performance in terms of power consumption. The data transmission uses a service, offered by the GSM network provider, converting traditional short messages (SMS) into messages, that are delivered almost immediately, so enabling to use the system for real time monitoring. The reliability of the data transmission system is high, depending on the Cellular Telephone Company, and surely is better and cheaper than a network of dedicated radio links managed by the buoy owner. The global data path is fault tolerant: A copy of the is stored in the measuring buoy. In case of problems with the receiving mail server, the mail messages will have a latency time during which the sending server will retry the delivery. The received mails are immediately downloaded into the data base computer, and a copy remains for some time in the mail server. Periodic back-up operations are performed on the data base. The use of enables to allocate the data centre in the most convenient place, without any need of proximity to the platforms: in fact the data acquired by all the buoys are collected and managed in Messina. The flexibility in mission programming, given by the execution of simple sequence files, allows to fit the measurements to the different and varying requirements of scientific research and environment monitoring (e.g. early warning or follow-up of pollution phenomena). The standard interval between

9 11 measurements is one hour, but it is possible to program the sequence files (24, one for each hour) to obtain higher or lower frequency, the only limit deriving from the time needed by the measuring instruments and from power consumption. The systems are fully automatic, and can be remotely controlled using a modem connected to a PC, or sending an SMS. It is also possible to disable the sequence manager, so stopping the execution of measurements (for instance during maintenance operations) without shutting down the buoy. The ability to remotely reprogram not only the sequence files, but also the main software enables to upgrade the systems without opening the watertight computer box. In the second half of 2003, new tests started to further upgrade the transmission system, with the use of new GSM-GPRS modems, in order to overcome the SMS length limitation and costs, connecting directly to the mail server. First tests were performed using a Siemens modem with Datalight Sockets to manage Internet connection; the device worked fine, but some difficulties were experienced in the integration with the existing control software. No difficulties, instead, were found using a Wavecom modem with embedded TCP-IP stack; with simple commands (similar to those used to send SMS) it is possible to send s and manage IP connections. This latter device will be used in the new release of the system, that is now under development. Acknowledgement The work here described was funded by the SAM and PI-CNR programs of the MIUR Cluster 10. References [1] Grisard, K., Eight years experience with the Elbe Estuary environmental survey net. Proc. of OES-IEEE OCEANS 94 Conference, I, pp , [2] Griffiths, G., Davis, R., Eriksen, C., Frye, D., Marchand, P., Dickey, T., Towards new platform technology for sustained observations. Proc. of OceanObs 99. Online [3] Paul, W., Buoy Technology. Marine Technology Society Journal, 35 (2), pp , [4] Seim, H., Werner, F., Nelson, J., Jahnke, R., Mooers, C., Shay, L., Weisberg, R., Luther, M., Proc. of SEA-COOS: Southeast Atlantic Coastal Ocean Observing System. MTS-IEEE OCEANS 2002 Conference, I, pp , [5] Pinardi, N., Allen, I., Demirov, E., De Mey, P., Korres, G., Laskaratos, A., Le Traon, P.Y., Maillard, C., Manzella, G., Tziavos, C., The

10 12 Mediterranean Ocean Forecasting System: first phase of implementation ( ). Annales Geophysicae, 21, pp. 3-20, [6] Zappalà, G., Caruso, G., & Crisafi, E., The SAM integrated system for coastal monitoring. Proc. of the 4th Int. Conf. On Environmental Problems in Coastal Regions, Coastal Environment IV, ed. C.A. Brebbia, WIT Press: Southampton, pp , [7] Crisafi, E., Azzaro, F., Zappalà, G., Magazzù, G., Integrated automatic systems for oceanographic research: some applications. Proc. of OES- IEEE OCEANS 94 Conference, I, pp , [8] Zappalà, G., Alberotanza, L., Crisafi, E., Assessment of environmental conditions using automatic monitoring systems. Proc. of MTS-IEEE OCEANS 99 Conference, II, pp , [9] Zappalà, G., Advanced technologies: equipments for environmental monitoring in coastal areas. Science-technology synergy for research in marine environment - Developments in Marine Technology, eds. L. Beranzoli, P. Favali, and G. Smriglio, Elsevier: Amsterdam, pp , [10] Zappalà, G., Caruso, G., Crisafi, E., Design and use of advanced technology devices for sea water monitoring. Operational Oceanography. Implementation at the European and regional Scales, eds. N.C. Flemming, S. Vallerga, N. Pinardi, H.W.A. Behrens, G. Manzella, D. Prandle, and J.H. Stel, Elsevier: Amsterdam, Oceanography Series, 66, [11] Lessing, P., Henderson, D., Architecture and development of an environmental acquisition and reporting system. Proc. of MTS-IEEE OCEANS 99 Conference, II, pp , [12] Bergamasco, A., Crisafi, E., Decembrini, F., A new e-tool to exploit data from an integrated monitoring approach for applied research and management purposes in coastal areas: the SAM project experience in Sicily (Italy). Seminario Una rete di progetti per lo sviluppo delle Scienze del mare nel Mezzogiorno d Italia: primi risultati del Piano Ambiente marino. Bari, 26 novembre Abstracts, p. 62.