| Figure 5: CMOSens® EM1 pin out. The electrical connector on the cover of the CMOSens® EM1 is a Molex PN 53014-0810 (straight header, male, 8Pin). You need a Molex PN 51004-0800 connector housing (female, 8 Pin) with crimp contacts Molex PN 50011-8100 to connect the sensor. Please check the Molex homepage for details (http://www.molex.com). 2.2 Power supply The CMOSens® EM1 Mass Flow Meter requires a voltage supply between 7V and 18 V. Since this voltage is internally regulated, there are no stringent requirements as far as ripple and stability are concerned. 2.3 Digital Interface The CMOSens® EM1 Mass Flow Meter has two interfaces: One is a bi-directional RS232 to set configuration and to get flow or temperature values. The other one is a uni-directional SPI that only sends flow or temperature depending on the configuration which was made by RS232. 2.4 Dataformat and Interpretation The received value is a 16 bit signed integer in the two's complement representation. The calibrated data is multiplied by a constant factor and then rounded to the next smaller integer in order to transfer also fractions of an unit through the integer protocol. This factor for flow is 128 for the EM1NV, 1 for the EM1NR and 50 for the EM1NL version. For the temperature for all versions the factor is 100. Example: a received value of +1234 (dec) corresponds either to 9.641 ln/min in flow mode or 12.34 °C in |