The purpose of this meeting was to discuss the feasibility of adding telemetry systems to the existing Buck Island CR10 hydrological data stations. It was determined that the SFWMD Okeechobee Tower can support a Buck Island telemetry system, if this system is made compatible with SFWMD hardware and software technology. It would be possible to implement this upgrade to the system with the purchase of required hardware ($28,000 for 20 sites or $1400 per site) from SFWMD-derived funds and provision of installation and programming services by SFWMD-trained IFAS technical staff funded by DEP.

The SFWMD currently uses Campbell Scientific RF95 modems with Johnson UHF radios (modified by SFWMD staff). The software conventions of SFWMD would require the fundamental restructuring of all CR10 controller programs to ensure compatibility with their communications and processing standards. A telemetry system also requires that each CR10 station have a 20W solar panel. I think we have 20W panels rather than 10W panels, but this would require confirmation.

The system recommended by SFWMD differs from the spread-spectrum system I originally proposed. SFWMD considers spread-spectrum systems to be inappropriate for their applications given the possibility of interference on thse public-access frequencies. In addition, I have recently found that the spread-spectrum technology when used with Campbell Scientific dataloggers requires additional hardware due to the non-standard nature of the Campbell RS232 system. I continue to work with IFAS engineers, Larry Miller and Dave Parker, on developing a true RS232 datalogger and spread-spectrum prototype since it has application to other monitoring sites.

Doug Wilkins also explained the SDI-12 communications protocol and its utility in field applications. This system allows multiple sensors to be driven off a single power-ground-data line of up to 500 feet in length. The data line is addressable thus allowing up to 10 SDI-12 devices to be monitored by a single control port. This might allow one CR10 to monitor as many as 80 SDI-12 devices. SFWMD has also been working with the Adcon company to combine the SDI-12 technology with the spread-spectrum technology to allow the SDI devices to transmit data to a central CR10 that would utilize standard RF telemetry for final data transmission. Such technology might have application to any new well water table monitoring system added to the pasture plots.

Daniel Yeck provided me with the SFWMD CR10 programs for their weather and stage stations. I will review these packages in anticipation of restructuring our current CR10 programs to this convention, should we move forward on the telemetry upgrade project.