GE RPT 301 user manual System Operation, Command Summary

RPT 301 User Manual 11

3 Operation

3.1System Operation

The frequency output from the sensor is counted for a fixed number of cycles. A mid-scale pressure gives a measurement period of approximately 0.5 seconds. During this time a high frequency clock is also being counted and at the end of the measuring cycle it is this value which is transferred to the processor for conversion into its pressure equivalent.

Measurement cycles are continuous, unless specifically interrupted (see the G command). Each cycle delivers a new pressure value to the programmable filter. The output of this filter is stored in a buffer and may be requested by the control computer or sent automatically at a programmable interval to the control computer.

3.2Command Summary

The instrument has a range of commands summarised in the table and detailed in this section. Some of these commands generate a reply from the instrument, the general format of these replies is given in section 3.4.

K177 Issue No. 3