The RA1216 is an intelligent 16 channel analog-to-digital converter. It also contains three digital-to-analog converters and parallel digital input/output ports. RA1216 communicatres with a host computer via opto-isolated asynchronous EIA RS485 half-duplex serial communications.
A built in watchdog timer resets the unit, if, for some unexpected reason, its microcontroller "hangs up", or if the power supply voltage drops below 4.75 VDC. The microntroller may also be reset by an external input. Data collected by the pod is stored in local RAM for later access through the host computer's serial port. This feature facillitates a stand-alone mode of operation.
The following paragraphs describe the major functional parts of RA1216.