# Middleware for Plug and Play Integration of Heterogeneous Sensor Resources into the Sensor Web
## 6 Use Cases
### EMSODEV Project  
The proposed acquisition chain has also been used within the EU-funded project EMSODEV. This project aims to develop the EMSO Generic Instrument Module (EGIM), as well as its associated  
Figure 16: SWE Bridge mission scheduler configuration for the SeaExplorer NeXOS mission. Figure 17: Sound Pressure Level (SPL) at 125 Hz octave band acquired by a SeaExplorer glider in a mission at the Norwegian coast. The incoming data from the hydrophone was subsampled and sent to shore in near real-time during deployment. Figure 15: SeaExplorer mission acquisition chain. data infrastructure. The EGIM is a compact-sized observation platform designed for long-term deployments at the EMSO nodes [45]. Its main purpose is to gather extensive, multidisciplinary data sets in a standardized fashion. In order to archive and distribute the acquired data, an SWE-based infrastructure is implemented. For collecting this multidisciplinary data, the EGIM includes an instrument pack of COTS sensors, shown in Table 1. The EGIM device with its instrument pack is shown in Figure 18.  
The EGIM has two modes of operation: autonomous and cabled. While in autonomous mode, the EGIM is powered by internal batteries and the data coming from the instruments is logged into CSV files, retrieved after the device recovery. On the contrary, when it is operated in cabled mode, it draws power from an external source, communicating the data in real-time using an Ethernet link. The EGIM implements a serial to Ethernet converters for each sensor, which are operated externally by an acquisition server. The EGIM device itself also sends data regarding its internal status using UDP frames. These frames contain information about input voltage, input current, remaining storage capacity, internal temperature and a leak detection alarm. Within the EMSODEV project, interoperability was also a matter of great concern. Thus, an SWE-based data acquisition process with the components presented in Section 3 was implemented [46]. Figure 19 shows the EMSODEV cyber-infrastructure in a cabled mode scenario. Each sensor is attached to the EGIM using RS232 ports, which converts this serial communication to an Ethernet link, providing a TCP/IP interface. The acquisition server runs an instance of the SWE Bridge for each instrument deployed on the EGIM node (except the hydrophone, which records data in its internal memory). A SDF file has been written for each sensor, available at [37]. As the sensors do not implement the OGC PUCK protocol (COTS sensors), these SDFs are stored locally in the acquisition server. Another instance of the SWE Bridge is also used to decode the EGIM internal status frames, which are treated as scientific data. The SWE Bridge generates O&M files containing the acquired data. These files are passed to an SOS proxy, which injects the data to an SOS server. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Sensor Type** & **Sensor Name** & **Manufacturer** & **Communication Link** \\ \hline CTD & SBE 37 & SeaBird Electronics & TCP/IP \\ Tsunami Meter & SBE 54 & SeaBird Electronics & TCP/IP \\ Oxygen Optode & Aanderaa 4831 & Aanderaa & TCP/IP \\ Turbidimeter & Eco NTU & Wetlabs & TCP/IP \\ ADCP & Workhorse & Teledyne & TCP/IP \\ Hydrophone & icListen & Ocean Sonics & FTP \\ EGIM Internal Status & EGIM & EMSODEV Consortium & UDP \\ \hline \hline \end{tabular}
\end{table} 
Table 1: EGIM Instrument Pack. The communications refers to the communications interface that the server uses to communicate to the sensors. Figure 18: EMSO Generic Instrument Module (EGIM) with its instrument pack during its deployment (**left**) and EGIM deployed at the OBSEA observatory (**right**). Within the EMSODEV project, the use of a Zabbix monitoring system to monitor the status of the EGIM and its associated cyber-infrastructure was proposed [47]. This monitoring system does not support O&M-based transactions.