CMMP logo

Chesil Multi-Media Project
CMMP Instrumentation System

The CMMP instrumentation system uses an RS485 bus running at 19,200 bits/sec to link a number of intelligent sensors. The information from the sensors complies with the NMEA183 sentence standard. Most sensors return data in response to a query command to minimise bus collisions.

This bus connects all the sensors to a command/interface unit that controls the sensor interrogation and combines the data into a single stream. The command/interface unit also handles the controls for the audio and video systems.

Air sensors
Air sensors

The data is linked to the Chesil Visitors Centre via a fibre-optic cable carrying bi-directional data.

At the Visitors Centre the data is displayed on a PC and also stored on the PC hard disk every minute.

The instrumentation bus is also used to carry command and response information for the video and audio systems.

Underwater sensor
Underwater sensor unit
Sensors currently available
Wind speed/direction Operational Located on Black Hut, at end of useful life and replacement imminent
Air temperature Operational Located on Black Hut, due for replacement with more accurate unit
Beach light levels Operational Located on Black Hut.
Beach temperature Operational Located 0.5 metres into beach behind Black Hut
Light level Operational Located on Black Hut
Black body temperature Operational Gives a measure of the power from the sun
Rainfall Operational Located on Black Hut
Barometer Operational Located in Black Hut
Beach vertical temperature profile Operational Surface sensor has intermittent fault. Measures four temperatures up to 1 metre into beach
Water temperature Operational Located on intertidal camera (P2). Needs to be replaced with deeper sensor


Last updated 20/10/2007 Copyright ©Chickerell BioAcoustics 2007