Wi-Fi débuts at GSL
An on-board serial-to-Ethernet converter allows you to install the 6TD directly onto a wired local area network. Clients using Scream can then connect to the instrument and receive data streams.
For temporary deployments with instruments buried in pits, stations can be contacted from a wireless-enabled PC running Scream! without requiring physical access. Real-time data can be examined and the digitizer configured over the wireless link.
For example, stations might be installed with high-gain antennae directed towards a visible natural feature which is easier to access. At this location, a low-power CMG-DCM data module would act as an access point for the array elements and forward data onto a higher-bandwidth radio link.
In semi-permanent arrays, a wireless-enabled DCM or laptop PC can be set up as a temporary access point for the duration of a site visit.
The CD24 compact digitizer, which provides the digital output features of newer CMG-6TD instruments, is also available as a separate device. Contact Guralp Systems for more information.
A PC running Scream! connected to each instrument over the wireless network and received data streams.
Using standard, off-the-shelf omnidirectional antennae, reliable continuous data flow was achieved from all instruments. The most distant instrument was located 20 m away through an area of significant interference. Another was placed at a straight-line distance of around 10 m, with signals passing through two exterior walls to reach the access point.
A second test was carried out under field conditions, using battery-powered CMG-6TD sensors equipped with +9dBa omnidirectional antennae.
Communication was easily established with all three installations using 1/8 of the receiving antenna’s maximum power, and streams were received overnight with no loss of data.
Guralp Systems are now working with research groups to perform detailed performance measurements under true experimental conditions.