The high speed buffer board : a SAIL EIA-485 communications accelerator card for the vector measuring current meter
Singer, Robin C.
Butler, Douglas M.
MetadataShow full item record
A High Speed Buffer Board (HSBB) has been developed for the Vector Measuring Current Meter (VMCM) to implement the transmission of data at 9600 baud over an EIA-485 link. The HSBB significantly extends the VMCM communication functionality, which was previously limited to 300 baud transmission via 20 mA current loop or FSK telemetry. The increased speed allows rapid sampling of a large number of current meters on a common cable and the EIA-485 circuitry, which was designed for low power operation, provides a useful multipoint communication method for data transmission over long cable lengths. SAIL protocol (IEEE 997) was utilized to coordinate data transfer by the instruments on a common link. An MC68HC11 microcontroller resides in the VMCM, buffering data it receives at 300 baud from the VMCM UART. In response to a jumper selectable SAIL address, the MC68HC11 offloads the data at 9600 baud via EIA-485 to the SAIL controller. Synchronous data collection from many instruments is ensured by the SAIL synoptic set command and an embedded resynchronization/reset command. The low power consumption allows deployments of six months or more with a standard VMCM battery stack.
Showing items related by title, author, creator and subject.
McCullough, James R.; Tupper, George H. (Woods Hole Oceanographic Institution, 1969-03)This report describes work done with Geodyne current meters and wind recorders during 1968. Techniques for testing instruments prior to use at sea, instrument performance at sea and instrument changes evolved during the ...
Deployment of a bottom monitor at a 30 meters deep site in the New York Bight Apex during the summer of 1993 Irish, James D. (Woods Hole Oceanographic Institution, 1993-09)A bottom instrument was deployed on May 5,1993, recovered and redeployed on June 22, 1993 and finally recovered on July 28, 1993 at a 30 meter site in the New York Bight Apex. The instrument measured currents, suspended ...
Trans-equatorial bottom water flow in the western Atlantic : volume XLVI in a series of reports presenting data from moored current meters Tarbell, Susan A.; Whitehead, John A.; Hall, Melinda M.; McCartney, Michael S. (Woods Hole Oceanographic Institution, 1997-02)Current and temperature measurements from Vector Averaging Current Meters (VACMs) deployed from September 1992 to June 1994 as part of the Deep Basin Experiment (DBE) measuring the trans-equatorial water flow are presented. ...