VISIBLE and UV SOLAR RADIOMETER PROCESSOR
NOTE!!!! PRELIMINARY REPORT ONLY!!! NOT COMPLETE OR NECESSARILY TOTALLY CORRECT
Data is collected from the two radiometers using the following circuits and controls.
See Block Diagram for a basic description.
Data is sent and received via a twin fiber optics (transmit and receive) cable running from the observatory to the meteorological tower site.
The individual devices attached to the processor are selected, polled, and the data read, by one byte commands from the observatory data collection computer.
As an example, see the block diagram , to read the visible radiometer, a "START CONV" (01h) command is sent to the processor.
This command is decoded and initiates a conversion of the analog signal (voltage) to a digital value (hexadecimal), by the Analog to Digital Converter. Upon completion of the conversion, the 12 bits (hex) are transferred to the Buffer Latches by the Status line of the A/D Converter indicating the conversion is complete.
Readout, and sending of the 12 bits is accomplished by two successive "READ" commands (READ H (20h)) and (READ L (40h)). These commands cause a readout of the data in the Buffer Latches, gating it to the Xmit UART. A delayed gate is used to generate "Data Strobe" initiating the transmission of data to the observatory.
To select the other radiometer, a "DEV ADD (04h)" command is issued that will toggle the selection switch. This switching command must be sent prior to the conversion command.
Developing schematics are located at the following pages:
Note!, These are NOT complete or fully tested yet.
Last update: 29 January 2004 Copyright RJA 1997 - 2004